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Supplements · Plant extracts
Pine Bark Extract: Benefits, Research, Dosage & Side Effects
What French maritime pine bark extract is, what the human trials show for blood flow, blood sugar, veins, joints, women's health and attention, how much to take and who should skip it.
Evidence-based56 sources citedUpdated October 15, 2026
The Dr. Axe Score™
Scientific Evidence
5.8/10
Dozens of placebo-controlled trials; pooled analyses show modest drops in blood sugar and blood pressure.
Bioavailability & Absorption
6.2/10
Its small compounds reach the blood within 30 minutes and stayed measurable through 14 hours of testing; gut bacteria turn the rest into an active metabolite.
Clinical Effectiveness
6.2/10
Measurable gains in blood vessel widening, blood sugar, leg swelling, menopause and period symptoms, and skin and hair.
Safety & Tolerability
8.4/10
Well tolerated in trials of up to 6 months, with mild stomach upset, dizziness or headache in a few people; not linked to liver injury.
Why this score?
Why Pine Bark Extract scores 6.5 / 10
Weighting: Evidence 30% · Bioavailability & Absorption 25% · Clinical Effectiveness 25% · Safety & Tolerability 20% (5.8×0.30 + 6.2×0.25 + 6.2×0.25 + 8.4×0.20 = 1.74 + 1.55 + 1.55 + 1.68 = 6.52, shown as 6.5). How we score
A transparent, weighted index built for supplements. See how it’s calculated →
Interaction check: Moderate. Blood thinners and antiplatelet drugs (warfarin, apixaban, rivaroxaban, clopidogrel, daily aspirin): in two groups of smokers, 22 heavy smokers on 100 mg and 16 others on 125 mg, the extract blocked smoking-induced platelet clumping as well as 500 mg of aspirin did, and one 200 mg dose kept working for more than 6 days, though bleeding time didn't rise on the extract alone; it hasn't been tested alongside an anticoagulant in people.51 If you take one, clear it with your prescriber first, and on warfarin, have your INR, the blood test that tracks how fast your blood clots, checked after you start. Diabetes medicines (insulin, sulfonylureas, metformin and others): the extract lowered blood sugar on top of standard treatment in placebo-controlled trials, so check your blood sugar more often, and have your prescriber adjust your doses as your numbers improve.202122 Blood pressure medicines: people on nifedipine needed less of it, and on ACE inhibitors, 58.3% kept their pressure controlled at half the dose, so check your blood pressure at home and let your prescriber adjust.3721 Immunosuppressants (after an organ transplant or for an autoimmune disease): the extract raised immune activity in mice, and it hasn't been tested alongside these drugs in people, so skip it unless the doctor who prescribes your medicine agrees.52
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Pine bark extract at a glance
Pine bark extract is a concentrated water extract of French maritime pine bark, rich in procyanidins, the family of polyphenols sold as OPCs, and its best-measured effect is helping your arteries widen.12
- Blood vessels: in a placebo-controlled trial in which each of 23 adults with heart disease tried both, 200 mg a day for 8 weeks raised flow-mediated dilation, a measure of how well an artery opens, from 5.3% to 7.0%, with no significant change on placebo2
- Blood sugar: across 13 trials in people with and without diabetes, pine bark extracts lowered fasting blood sugar by 6.25 mg/dL3
- Legs: in a placebo-controlled trial of 40 adults with varicose veins, about 60% of those taking 300 mg a day saw their swelling and leg pain disappear within 2 months4
- Attention: in a 10-week placebo-controlled trial of 88 children with ADHD, teacher-rated symptoms fell on 20 to 40 mg a day and on methylphenidate, with no difference between the two on the total score5
Pine bark extract is a purified water extract of the outer bark of the French maritime pine, a fine reddish-brown powder, and 65% to 75% of it is procyanidins, the polyphenols also sold as OPCs.1 That bark protects a pine that stands up to salt and frost and grows for 30 to 50 years along the coast of southwest France.16 In human trials, the extract helped arteries open more fully, lowered blood sugar modestly in type 2 diabetes, and eased leg swelling, knee pain, menopause symptoms and attention problems in children.
Its best-measured action is on the thin lining of your blood vessels, the layer that makes nitric oxide and tells an artery when to relax.7
Healthy arteries widen on demand, thanks to nitric oxide made in their lining.Dr. Josh Axe, DC, DNM, CNSWritten in The High Blood Pressure Protocol (2026), p. 12
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The U.S. Pharmacopeia carries a monograph for maritime pine extract, with tests for identity, purity, heavy metals and procyanidin content.1
In a randomized trial of 33 adults with severe knee osteoarthritis, 16 took 200 mg a day for 3 weeks before knee replacement and 17 took nothing; taxifolin, one of the extract's compounds, turned up in the fluid inside the knee joint only in those who took the extract.8
In a placebo-controlled trial of 91 adults with gum inflammation, after 3 months of 200 mg a day, a compound that gut bacteria make from the extract showed up in people's saliva, and those with more of it tended to have less bleeding from their gums.9
What is pine bark extract?
Quick answer
Pine bark extract is a concentrated water extract of the outer bark of the French maritime pine, Pinus pinaster, standardized to 65% to 75% procyanidins.1 Procyanidins are chains of catechin and epicatechin units, and the extract also carries smaller compounds such as taxifolin and caffeic and ferulic acid.110
Maritime pine, also called Pinus pinaster, is the tree behind the extract, and the subspecies used grows in the Landes de Gascogne, a forest along the coast of southwest France.6 The finished extract is taken as capsules or tablets.1
Its flavonoid compounds range from single units such as catechin and taxifolin to procyanidin chains of 7 or more units.10 The shorter chains, called oligomers, give OPCs their name: oligomeric proanthocyanidins. Grape skin, cocoa and green tea carry relatives of the same compounds, as the food section below shows.
The forest itself was planted: in the second half of the 1800s, the sparse heath and grazing land of the Landes was planted with pine.11 Scripture names the pine among the trees God promised to set in the desert: "I will set in the desert the fir tree, and the pine, and the box tree together" (Isaiah 41:19).
Other pine bark extracts are sold too, made from different trees, such as New Zealand's radiata pine, with their own processes and compositions.12 The research below names the product wherever a study used something other than the standardized French maritime extract.
Evergreen bark as medicine: a short history
The best-known evergreen bark remedy comes from the winter of 1535 to 1536, when the French explorer Jacques Cartier's ships sat frozen in the ice for five months at Stadaconé, on the St. Lawrence River.13 Almost all of his men fell ill with what would later be called scurvy, and 25 of the 112 sailors died that winter.13 The Iroquois of Stadaconé gave the crew a decoction of the bark and leaves of a tree they called annedda, and it worked quickly.1413 Researchers have proposed several conifers as annedda, and it's now commonly identified as arborvitae, the eastern white cedar; its decoction supplied the vitamin C the sailors were missing.14
The extract on shelves today comes from a different evergreen, the European maritime pine.1
What is pine bark extract good for?
Quick answer
Pine bark extract is best studied for blood vessel function and blood sugar, with further trials for leg swelling, knee pain, menopause symptoms, period pain, skin, hair and attention in children.23415165 Pooled analyses also found modest drops in blood pressure, though results varied with the design of the trials.1718
Where the research stands
The extract's maker counts 39 randomized, placebo-controlled trials with 2,009 people, running from two weeks to six months.6 A 2020 Cochrane review counted 27 randomized trials with 1,641 people across 10 conditions and rated the evidence very low certainty, mainly because the trials were small and few for each condition.19 The maker funded 20 of those 27 trials.19
| Use | Evidence | Product studied | What the research shows |
|---|---|---|---|
Blood vessel function | Moderate | French maritime pine bark extract, 180 to 200 mg a day, 2 to 8 weeks | Flow-mediated dilation 5.3% to 7.0%, with no significant change on placebo; a nitric oxide–dependent rise in forearm blood flow27 |
Blood sugar | Moderate | Several pine bark extracts pooled; French maritime extracts, 100 to 125 mg a day, in the type 2 diabetes trials | Fasting blood sugar down 6.25 mg/dL and HbA1c down 0.32 percentage points in people with and without diabetes; lower blood sugar or HbA1c in 3 type 2 diabetes trials3202122 |
Blood pressure | Mixed | Several pine bark extracts, including a water-based Japanese extract | Systolic down 2.26 to 3.22 points in two pooled analyses; no significant change in a third limited to 7 trials1731823 |
Leg swelling and varicose veins | Emerging | French maritime pine bark extract, 300 mg a day, 2 months | Swelling and pain disappeared in about 60%4 |
Knee and joint pain | Emerging | French maritime pine bark extract, 100 to 150 mg a day, 3 months | Large short-term pain relief; WOMAC score down 56%, against 9.6% on placebo152425 |
Attention in children with ADHD | Emerging | French maritime pine bark extract, 20 to 40 mg a day or 1 mg per kg | Teacher-rated scores 26.07 to 18.43; no difference from methylphenidate on the total score526 |
Menopause and period pain | Emerging | French maritime pine bark extract, 60 to 200 mg a day | Menopause symptom score down 56%, against 39% on placebo; fewer days needing pain medicine with painful periods162728 |
Skin, hair and dark spots | Emerging | French maritime pine bark extract, 100 to 150 mg a day, 2 to 6 months | Hair density up 30% from the start at 2 months; a bigger drop in melasma score than placebo, alongside sunscreen and a lightening cream; better skin hydration and elasticity293031 |
Erectile function | Emerging | French maritime pine bark extract combined with L-arginine | Erectile function score up 8.9 points more than placebo in the 2 trials that measured it; better satisfaction, orgasm and desire32 |
How does pine bark extract work in your body?
Pine bark extract works in two stages: its small compounds are absorbed within minutes, and gut bacteria turn its larger procyanidins into a metabolite that reaches your blood vessels hours later. The best-measured result is more nitric oxide from the lining of your arteries. In my High Blood Pressure Protocol, I call that lining the hinge: when it loses nitric oxide, the molecule that lets arteries relax and widen, pressure climbs.33
Here's how the research fits together, step by step:
1What's in the capsule
The studied extract is 65% to 75% procyanidins, chains of catechin and epicatechin, along with catechin itself, taxifolin and phenolic acids such as caffeic and ferulic acid.1
2Fast absorbers
The small compounds are absorbed in the small intestine and show up in the blood within 30 minutes.1 After a single 300 mg dose in 11 volunteers, catechin reached about 60 ng/mL at half an hour, and most compounds stayed measurable for the full 14 hours of testing.34
3Gut bacteria do the rest
Up to 90% of the procyanidins reach the colon intact, where gut bacteria break them into a small metabolite, M1, that enters the blood.1 In cell studies, blood vessel lining cells and immune cells pull M1 inside and concentrate it, and there it reduced the activity of iNOS, the enzyme that overproduces nitric oxide during inflammation, a different enzyme from the one your vessel lining uses to relax arteries.35
4The vessel lining makes more nitric oxide
In a placebo-controlled trial of 16 healthy young men, the 8 who took 180 mg a day for 2 weeks saw the forearm's blood-flow response rise from 13.1 to 18.5 mL per minute per 100 mL of tissue, with no change on placebo, and blocking the enzyme that makes nitric oxide erased the gain.7
5Inflammatory enzymes quiet down (proposed)
In lab tests of blood from 10 volunteers who took a single 300 mg dose of the extract, their plasma slowed COX-1 and COX-2, the enzymes many pain relievers target, within 30 minutes.36 Researchers propose this as one reason for its effects on joint and period pain.
Absorption varies from person to person: in a trial of adults with severe knee osteoarthritis, the levels of each compound in blood and joint fluid differed considerably between individuals.8
Pine bark extract benefits: what the human trials show
Ranked by the strength of the human research, pine bark extract's benefits start with blood flow and blood vessel function and blood sugar, followed by leg swelling and varicose veins, joint pain, attention in children, menopause and period pain, and skin and hair.
1
Blood flow and blood vessel function
Moderate evidenceHuman studyPlacebo-controlled trials of 23 and 58 adults; pooled analyses of 12 trials and of 21 effect sizesIn a placebo-controlled trial in which each of 23 adults with stable coronary artery disease tried both, 200 mg a day for 8 weeks, on top of their usual heart medicines, raised flow-mediated dilation from 5.3% to 7.0%, with no significant change on placebo (5.4% to 4.7%), and a marker of oxidative stress fell; inflammation markers, platelet stickiness and 24-hour blood pressure didn't change.2 The nitric oxide trial behind that effect is in the step diagram above.
Blood pressure came down modestly in pooled analyses: 3.22 points systolic and 1.91 diastolic across 12 trials with 922 people, and 2.26 and 2.62 points in a 2025 analysis that pooled several pine bark products, including some studies that weren't randomized.173 An analysis limited to the 7 trials in which neither the people nor the researchers knew who got what, with 626 people, found no significant change in blood pressure, and neither did a 130-person trial of a different, water-based pine bark extract.1823 In a placebo-controlled trial of 58 people with high blood pressure who were taking nifedipine, those on 100 mg a day for 12 weeks needed less of the drug to keep their pressure controlled.37
My High Blood Pressure Protocol rebuilds nitric oxide with food first: beets and leafy greens above all, garlic and polyphenol-rich color, plus sunlight and easy movement.33 If you add pine bark extract, add it on top of that foundation, along with these natural ways to lower blood pressure.
Study takeaway: in a placebo-controlled trial in which each of 23 adults with heart disease tried both, 200 mg a day raised flow-mediated dilation from 5.3% to 7.0% in 8 weeks.
2
Lower blood sugar
Moderate evidenceHuman studyPooled analysis of 13 and 6 trials; placebo-controlled trials of 77, 48 and 46 adultsIn a 2025 analysis of trials in people with and without diabetes, among them people with metabolic syndrome, high blood pressure or heart disease, pine bark extracts lowered fasting blood sugar by 6.25 mg/dL across 13 trials and HbA1c, your three-month blood sugar average, by 0.32 percentage points across 6 trials, with the HbA1c result rated moderate certainty.3 In the same analysis, body weight came down 1.37 kg, about 3 pounds, across 8 trials, a result rated high certainty.3
The trials in type 2 diabetes show the same direction. In a placebo-controlled trial of 48 adults with type 2 diabetes and mild to moderate high blood pressure, 125 mg a day for 12 weeks lowered fasting blood sugar by 23.7 mg/dL, against 5.7 on placebo, and HbA1c by 0.8 points, against 0.1; LDL fell 12.7 mg/dL, and 58.3% of those on the extract kept their blood pressure controlled on half their usual ACE-inhibitor dose.21 In a placebo-controlled trial of 77 people with type 2 diabetes who kept up their usual treatment, 100 mg a day for 12 weeks lowered blood sugar more than placebo, while HbA1c was lower than on placebo only at the first month.20 And in a placebo-controlled trial of 46 adults with type 2 diabetes and microalbuminuria, an early sign of kidney strain, another French maritime pine bark extract at 100 mg a day for 8 weeks lowered HbA1c, the urine albumin-to-creatinine ratio, total cholesterol and waist size more than placebo, while fasting blood sugar, insulin, triglycerides, LDL and HDL didn't differ.22
Diet, movement and fat loss do the main work of bringing blood sugar down; the free Type 2 Diabetes Protocol lays out those steps, and our guide to normal blood sugar explains the numbers.
Study takeaway: in a 2025 analysis, pine bark extracts lowered fasting blood sugar by 6.25 mg/dL across 13 trials in people with and without diabetes.
Fasting blood sugar fell 6.25 mg/dL across 13 trials of pine bark extracts
3
Less leg swelling with varicose veins
Emerging evidenceHuman studyPlacebo-controlled trial · 40 adults with chronic venous insufficiency · 2 monthsIn a placebo-controlled trial of 40 adults with chronic venous insufficiency and varicose veins, 300 mg a day for 2 months reduced swelling, heaviness and leg pain at 30 and 60 days, and about 60% of those on the extract saw their swelling and pain disappear completely by the end; blood flow in the leg veins, measured by ultrasound, didn't change in either group.4
My top remedies for varicose veins are butcher's broom, horse chestnut and bilberry, with ginkgo and collagen or bone broth, plus exercise such as yoga, walking, cycling and swimming.38 Pine bark extract's trial results make it one more option to use alongside them.
Study takeaway: in a placebo-controlled trial, about 60% of adults with varicose veins taking 300 mg a day saw swelling and leg pain disappear in 2 months.
4
Joint pain from osteoarthritis
Emerging evidenceHuman studyAnalysis of 69 trials of 20 supplements; placebo-controlled trials of 156 and 100 adults · 3 monthsAn independent 2018 analysis of 69 trials of 20 supplements for osteoarthritis of the hand, hip and knee placed pine bark extract among 7 supplements with a large, clinically important drop in pain over the short term.15
In a placebo-controlled trial of 156 adults with osteoarthritis, 100 mg a day for 3 months lowered the WOMAC score, a combined measure of pain, stiffness and function, by 56%, against 9.6% on placebo, walking distance on a treadmill rose from 68 to 198 meters, against 65 to 88 meters on placebo, and use of anti-inflammatory drugs fell 58%, against 1%.24 In a placebo-controlled trial of 100 adults with early knee osteoarthritis, 150 mg a day with meals for 3 months improved WOMAC scores and pain, and painkiller use fell on the extract while it rose on placebo.25 For more options, see knee pain relief and these natural treatments for arthritis.
Study takeaway: in an analysis of 69 trials, pine bark extract was among 7 supplements with large short-term pain relief for osteoarthritis.
5
Attention in children with ADHD
Emerging evidenceHuman studyPlacebo-controlled trials of 88 and 61 children; trial of 24 adults in which each person tried all threeIn a 10-week trial of 88 children with ADHD, ages 6 to 12, in which neither the families nor the researchers knew who got what, French maritime pine bark extract at 20 or 40 mg a day, by body weight, lowered teacher-rated ADHD scores from 26.07 to 18.43; methylphenidate lowered them from 24.77 to 13.50, and placebo moved them from 30.06 to 28.60.5 Both treatments beat placebo on the total and hyperactivity scores and didn't differ from each other on those scores; only methylphenidate improved inattention and the parents' ratings, and side effects were reported significantly more often on the medicine.5 Twelve children (14%) dropped out.
In a second placebo-controlled trial of 61 children, 1 mg per kg of body weight a day for 4 weeks lowered hyperactivity and improved attention and coordination on teacher and parent scales, and symptoms returned a month after the children stopped.26 In 24 adults who each tried the extract, methylphenidate and placebo for 3 weeks, symptoms improved during treatment but neither active treatment beat placebo.39
For a child, my first step is food: get artificial dyes out of your home, since Red 40, Yellow 5 and Yellow 6 are among the dyes linked to hyperactivity and behavioral problems in kids.40 Use pine bark extract for a child only with the doctor who manages the child's ADHD, at the trial doses, and never stop or swap a prescribed ADHD medicine on your own.
Study takeaway: in a 10-week placebo-controlled trial of 88 children with ADHD, teacher-rated scores fell from 26.07 to 18.43 on 20 to 40 mg a day.
Teacher-rated ADHD scores fell on pine bark extract and on methylphenidate
6
Menopause symptoms and period pain
Emerging evidenceHuman studyPlacebo-controlled trials of 170, 155 and 116 womenIn a placebo-controlled trial of 170 women in perimenopause, 156 of whom finished, 60 mg a day for 3 months lowered the Kupperman index, a standard menopause symptom score, by 56%, against 39% on placebo, and hot flashes and sleep problems improved more than on placebo at 4 and 12 weeks.16 In a second placebo-controlled trial, which 155 women in perimenopause completed, 200 mg a day improved every group of symptoms the questionnaire scored, raised antioxidant levels in the blood and improved the LDL-to-HDL ratio.27 The free Perimenopause & Menopause Protocol covers the steps that come first.
For painful periods, a placebo-controlled trial of 116 women aged 18 to 48 gave 60 mg a day for two menstrual cycles. In the women with painful periods, pain eased and they needed pain medicine on fewer days, an effect that lasted one cycle after they stopped; women with mild period pain saw no difference.28 See period cramps for more natural relief.
Study takeaway: in a placebo-controlled trial of 170 women in perimenopause, 60 mg a day lowered menopause symptom scores 56%, against 39% on placebo.
7
Skin, hair and dark spots
Emerging evidenceHuman studyPlacebo-controlled trials of 76 outdoor workers, 76 women after menopause and 44 women with melasma; study of 20 womenIn a placebo-controlled trial in which each of 76 outdoor workers in Beijing tried both, 100 mg a day for 12 weeks kept skin from drying out and darkening as the seasons changed, and improved its elasticity, effects not seen on placebo.29 In 20 healthy women after menopause who took the extract for 12 weeks, with no comparison group, skin hydration and elasticity improved, most in dry skin, along with the activity of genes that build collagen and hyaluronic acid.41
Hair responded too. In a placebo-controlled trial of 76 women after menopause, 63 of whom were analyzed, 150 mg a day raised hair density by 30% at 2 months and 23% at 6 months, from 225.8 hairs per square centimeter to 293.6 and then 278.6, while the smaller rise on placebo, from 226.6 to 255.6 and then 247.7, wasn't significant.30 And in 44 women with melasma, a form of hyperpigmentation, who all used sunscreen and a nightly prescription lightening cream, adding 150 mg a day for 60 days lowered the melasma score more than placebo did.31 For more natural options, see these hair loss remedies.
Study takeaway: in a placebo-controlled trial of women after menopause, 150 mg a day raised hair density 30% at 2 months.
Hair density rose on pine bark extract in women after menopause
For men: erectile function and blood flow
Erections depend on blood flow, and the trials in men tested pine bark extract combined with L-arginine, the amino acid your body uses to make nitric oxide. A 2023 review gathered 3 placebo-controlled trials with 184 men with mild to moderate erectile dysfunction. In the 2 trials it could pool, the combination raised the erectile function score 8.9 points more than placebo and improved satisfaction, orgasm and desire, and the third, which used a shorter questionnaire, also found better erectile function; pooled testosterone levels didn't differ significantly from placebo.32 In one of those trials, 50 men who each tried the combination and a placebo for a month reported better erectile function and more frequent intercourse on the combination.42
My High Blood Pressure Protocol lists L-arginine, with L-citrulline, in its advanced tier as a nitric oxide precursor, an add-on to nitrate-rich foods used with a practitioner.33
More research: memory, breathing, allergies, gums and eyes
Single trials have tested other uses:
| Use | Who and design | What happened |
|---|---|---|
Memory in older adults | 101 healthy adults aged 60 to 85, placebo-controlled, 150 mg a day for 3 months | Better working memory and lower F2-isoprostanes, a marker of fat oxidation, than placebo43 |
Asthma in children | 60 children aged 6 to 18 with mild to moderate asthma, placebo-controlled, 3 months, added to usual care | Better lung function and symptoms; more could cut back or stop their rescue inhalers44 |
Birch-pollen allergy | 39 people who started 5 to 8 weeks before the season, placebo-controlled | Eye symptoms 35% and nasal symptoms 20.5% lower than placebo; no difference in 19 who started 3 weeks before45 |
Gum inflammation (gingivitis) | 91 adults after a professional cleaning, placebo-controlled, 100 mg twice a day for 3 months | Lower inflammation markers in saliva and blood9 |
Early diabetic retinopathy | 46 people with diabetes, placebo-controlled, 3 months | Less swelling in the retina and sharper vision46 |
For ways to improve memory with food and daily habits, see our guide.
Four markers that show where you stand
These markers track the same things the pine bark extract trials measured and give you a baseline to retest against. None of them measures the extract itself. Review your numbers with your practitioner.
- Blood pressure at home: A week of morning and evening readings gives you a baseline; pooled trials found modest systolic drops.173
- Fasting glucose and HbA1c: Your blood sugar today and over about three months, the two blood sugar numbers that fell in pooled trials of the extract.3
- LDL and HDL cholesterol: LDL fell about 5 mg/dL across 14 trials in the 2025 analysis, and HDL cholesterol rose about 3 mg/dL across 14 trials in a 2019 analysis; each analysis found no significant change in the other.347
- hs-CRP: A sensitive blood measure of inflammation, also called C-reactive protein; it fell in a pooled analysis of 5 trials with 324 people, with results that varied widely between them.48
See the cellular bloodwork panel
Have results? Analyze them free →How to take pine bark extract: dosage and timing
Quick answer
The adult trials on this page used 60 to 300 mg a day of French maritime pine bark extract, most often 100 to 200 mg a day, for 2 weeks to 6 months.62416 Match the dose to the trial that studied your goal, in the table below.
| Goal | Daily amount studied | How long |
|---|---|---|
Blood vessel function | 200 mg | 8 weeks2 |
Blood sugar, type 2 diabetes | 100 to 125 mg | |
Leg swelling and varicose veins | 300 mg (100 mg three times a day) | 2 months4 |
Knee osteoarthritis | 100 to 150 mg | |
Menopause symptoms | 60 mg (30 mg twice a day) | 3 months16 |
Painful periods | 60 mg | 2 menstrual cycles28 |
Hair density | 150 mg (50 mg three times a day) | 6 months30 |
Memory, older adults | 150 mg | 3 months43 |
Stomach upset is among the side effects reported, so with a sensitive stomach, take it with a meal, the way the 3-month knee trial gave it.3725 Splitting a larger amount into two or three doses across the day matches how several trials gave it.41630
How long it takes depends on the goal: leg swelling eased by 30 days, menopause symptoms by 4 weeks, hair density rose by 2 months, blood vessel function improved within 2 to 8 weeks, and blood sugar fell over 8 to 12 weeks.41630722122
How to choose a pine bark extract
Pine bark extracts aren't all the same product, so the label tells you whether you're buying what the trials tested:
The tree named on the label: French maritime pine, Pinus pinaster, is the species behind most of the single trials on this page.1
A stated procyanidin content: the studied extract is standardized to 65% to 75% procyanidins and meets the U.S. Pharmacopeia's maritime pine extract monograph.1
Third-party testing for identity, purity and heavy metals, with results the maker will share.
Milligrams of extract per capsule, so you can match the amount to the trial for your goal.
Getting OPCs from food
Nobody eats pine bark, so the extract is how you get its procyanidins. The same polyphenol family also comes in foods you can eat every day. My list of foods for the heart and blood includes dark chocolate, in moderation, for its flavanols, which improve the function of the vessel lining; green tea for its catechins, which improve vascular elasticity; berries, whose anthocyanins protect the vascular lining; and garlic and onions as natural nitric oxide boosters.49
Grapes carry them too. As I said on my show, "Grape skin is packed with OPCs. It's also packed with resveratrol."50 Resveratrol has its own guide.
Want help fitting pine bark extract into your routine?
Ask Dr. Axe AI. Answers are grounded in this library, with sources shown.
Pine bark extract side effects, interactions and who should skip it
Quick answer
Pine bark extract has been well tolerated in trials of up to 6 months, with mild, short-lived stomach upset, dizziness, headache or nausea in some people, at rates that didn't differ from placebo in the early diabetes and blood pressure trials.193720 It hasn't been linked to liver enzyme rises or liver injury.53
LiverTox, the National Institutes of Health database on liver injury from drugs and supplements, lists pine bark as generally recognized as safe.53 In the ADHD trial in children, the extract's side effects were headache, dizziness, nausea and diarrhea.5
The newest safety data come from a 12-week placebo-controlled trial of 153 adults with long COVID, posted in 2025 and not yet peer reviewed. On 200 mg a day, there were 31 adverse events, against 18 on placebo; 11 and 9 were judged probably related, and none of the three serious events was linked to either product.54 In one documented case, a healthy 35-year-old man who had taken more than the label's recommended amount developed severe muscle breakdown, called rhabdomyolysis, after lifting furniture; the case report rated the link to the extract as possible.55 Stay within the amounts the trials used.
Good to know before you take pine bark extract:
Pregnancy and breastfeeding: one study gave 30 mg a day late in pregnancy for back, hip and pelvic pain and reported no unwanted effects, but that's too little data to establish safety, so skip it while you're pregnant or nursing.56
Planned surgery or dental surgery: stop at least a week before, and tell your surgeon you've been taking it, since one 200 mg dose affected platelets for more than 6 days.51
Muscle pain and dark urine: stop taking it and get medical care right away for severe muscle pain or weakness with tea-colored urine.55
Long-term use: the placebo-controlled trials ran up to 6 months; if you take it longer, review it with your practitioner along with your bloodwork.619
The bottom line
Is pine bark extract worth taking?
For adults who want to support blood flow, blood sugar or circulation in the legs, yes. Pine bark extract concentrates the procyanidins of the French maritime pine, and in human trials it helped arteries open more fully, lowered blood sugar modestly in type 2 diabetes and eased leg swelling, with further trials for knee pain, menopause symptoms, skin, hair and attention in children. The trials of this extract point in an encouraging direction.
Take 100 to 200 mg a day, the range most adult trials used, matched to your goal. If you're pregnant, nursing or facing surgery, or you take a blood thinner, diabetes or blood pressure medicine, or an immunosuppressant, read the safety section first. Your arteries were designed to widen on demand, and good food, daily movement and well-chosen support help them do it.
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Five steps in order, from calming the drivers of high pressure to restoring nitric oxide with beets and leafy greens, plus the minerals your vessels relax on and a meal plan. Have recent bloodwork? Analyze it free. Free with your Dr. Axe account (email or Google). You'll also get the protocol's short email series and the Dr. Axe newsletter; unsubscribe anytime.
Open the free protocol →Pine bark extract: frequently asked questions
What is pine bark extract good for?
Pine bark extract is best studied for blood vessel function and blood sugar: it raised flow-mediated dilation from 5.3% to 7.0% in a placebo-controlled trial in which each of 23 adults with heart disease tried both, and lowered fasting blood sugar 6.25 mg/dL across 13 trials in people with and without diabetes.23 Trials also support it for leg swelling, knee pain, menopause symptoms, period pain, skin, hair and attention in children.415165
What does pine bark extract do for men?
Combined with L-arginine, it improved erectile function: in a review of 3 placebo-controlled trials with 184 men with mild to moderate erectile dysfunction, the 2 trials it could pool showed the erectile function score rising 8.9 points more than placebo, along with better satisfaction, orgasm and desire.32 On its own, the extract improved nitric oxide–driven blood flow within 2 weeks in a placebo-controlled trial of 16 healthy young men, 8 of whom took it.7
What does pine bark extract do for women?
In placebo-controlled trials in women, it eased menopause symptoms, cutting a standard symptom score 56% against 39% on placebo in a trial of 170 women, and reduced pain-medicine days for painful periods.1628 It also raised hair density 30% at 2 months in a placebo-controlled trial of women after menopause, and in 20 women after menopause, with no comparison group, skin hydration and elasticity improved.3041
Does pine bark extract lower blood pressure?
Modestly, in pooled analyses: systolic pressure fell 3.22 points across 12 trials and 2.26 points in a 2025 pooled analysis.173 An analysis limited to 7 trials in which neither the people nor the researchers knew who got what found no significant change, so its clearest effect is on how well arteries widen.182
Does pine bark extract lower blood sugar?
Yes, modestly: across 13 trials in people with and without diabetes, pine bark extracts lowered fasting blood sugar by 6.25 mg/dL, and across 6 trials, HbA1c by 0.32 percentage points.3 If you take diabetes medicine, read the interaction check in the safety section first.
Does pine bark extract help varicose veins?
It eased the swelling and pain that come with them: in a placebo-controlled trial of 40 adults with varicose veins and chronic venous insufficiency, about 60% of those taking 300 mg a day saw swelling and leg pain disappear within 2 months, and nearly all said their legs felt less heavy.4
Can pine bark extract help with ADHD?
It helped in trials: in a 10-week placebo-controlled trial of 88 children aged 6 to 12, 20 to 40 mg a day lowered teacher-rated ADHD scores from 26.07 to 18.43, with no difference from methylphenidate on the total score, though only the medicine improved inattention and parent ratings.5 Use it for a child only with the doctor who manages the ADHD.
How much pine bark extract should I take a day?
How long does pine bark extract take to work?
Is pine bark extract safe to take every day?
What are the side effects of pine bark extract?
The side effects reported in trials were mild and short-lived: stomach upset, dizziness, headache and nausea, at rates that didn't differ from placebo in the early diabetes and blood pressure trials.3720 In one 12-week placebo-controlled trial of 153 adults, posted as a preprint, more adverse events were logged on the extract than on placebo, 31 against 18, but about as many were judged probably related to each product, 11 against 9, and none of the three serious events was linked to either.54
Who should not take pine bark extract?
Is pine bark extract the same as OPCs or grape seed extract?
Are all pine bark extracts the same?
No: extracts are made from different pine species, such as French maritime pine and New Zealand radiata pine, with different processes and compositions.121 Most of the single trials on this page tested a French maritime pine bark extract standardized to 65% to 75% procyanidins, so check the label for the species and the procyanidin content.1
Can you make pine bark tea?
Not one that matches the research: the trials used a concentrated water extract of maritime pine bark, taken as capsules or tablets, not a tea.1 The bark-and-leaf decoction that helped Jacques Cartier's crew recover from scurvy came from a tree now commonly identified as arborvitae, and pine needle tea and pine oil are different products again.14
Is white pine bark the same as pine bark extract?
No. The single trials on this page tested extracts of French maritime pine bark, Pinus pinaster, a different tree from white pine, and white pine bark wasn't part of that research.1
Freshness & update log
October 15, 2026 — Rewrote the page in full. Adds the Dr. Axe Score under the current supplement weighting (6.5) with an interaction check (Moderate: blood thinners, diabetes and blood pressure medicines, immunosuppressants); reports the human trials for blood vessel function, blood pressure, blood sugar, leg swelling, joint pain, attention in children, menopause, period pain, skin, hair and erectile function with their designs and numbers, including the trials that found no difference; adds three charts, a step diagram, a dosage table and a buying checklist; corrects the extract's composition (65% to 75% procyanidins) and the history (Cartier's winter of 1535 to 1536, and the annedda tree, now commonly identified as arborvitae); gathers the safety guidance in one section; and adds a FAQ and references. Removed earlier claims that rested on animal or lab studies, other products or no source: hearing loss and balance, ear and bacterial infections, surgical wounds, athletic performance, sperm counts, and a warning about taking OPCs with vitamin C.
April 28, 2024 — Previous version published.
References
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- Axe J. The High Blood Pressure Protocol. DrAxe.com; 2026 (p. 5, "The core mechanism": the vessel lining as the hinge, where low nitric oxide leaves arteries unable to relax and widen; p. 12, Step 3, "Open": "Healthy arteries widen on demand, thanks to nitric oxide made in their lining," with beets and leafy greens, garlic and polyphenol-rich color, sunlight and easy movement; p. 17, tiered supplement protocol: L-citrulline / L-arginine as nitric-oxide precursors in the advanced tier, with a practitioner).
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- Axe J. Ancient Remedies. Little, Brown Spark; 2021. Prescriptions for 70+ Conditions: varicose veins, p. 284 (butcher's broom, horse chestnut, bilberry, ginkgo biloba, bone broth or collagen powder; exercise such as yoga, walking, cycling and swimming).
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- Axe J, Rubin J. The Biblio Diet. Hachette Book Group; 2025. ISBN 9781546008439. "The Sinister Six" (artificial colors: Blue 1 and 2, Red 3 and 40, Yellow 5 and 6, Green 3 and Orange B linked to hyperactivity and behavioral problems in kids) and "Take Action Now" (get rid of artificial dye at home).
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- Axe J, Rubin J. 8 Secrets to Boost Testosterone for Men and Women. The Dr. Axe Show. 2017 (Dr. Axe at 27:11; YouTube https://www.youtube.com/watch?v=_sMkl9fVfoE&t=1631).
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