Agar Agar: Benefits, Nutrition, Recipes & How to Use It

Agar agar, often just called agar, is a plant-based gel made from red algae, and in your kitchen it does the job of gelatin, setting puréed fruit, coconut milk or broth into a firm jelly that holds its shape at room temperature.26 In your body it works as fiber, which most diets run short on, since the average person eats around 15 grams of fiber a day, and I want you closer to 30 to 40.7

Agar is about four-fifths fiber by weight, so every jelly, pudding or bowl of agar noodles adds some of the soluble, gel-forming kind back to your plate.1 When you're often constipated, or hungry again soon after a meal, a diet that runs short on fiber is often part of the root cause, and agar is a simple way to bring that fiber back, because it slows how quickly your stomach empties and adds soft, water-holding bulk to your stool.34 It's also the plant-based way to make gummies, marshmallows and panna cotta without gelatin, much of which comes from pig skin.8

Japanese cooks have been making agar desserts, which they call kanten, since the mid-1600s,2 and pharmacopoeias in Japan, Britain and the United States listed agar as a mild laxative.46 The human studies point the same way: agar brought more regular bowel movements, kept a meal in the stomach longer and, as a small jelly before dinner, helped people with obesity lose more weight.345

Did you know?

• Agar was the first seaweed gel ever extracted, about two centuries before carrageenan.2

• In water, agar can swell to more than five times its volume within 4 hours.6

• Because most bacteria can't break it down, agar is also the firm gel microbiologists grow bacteria on in lab dishes.9

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What is agar agar?

Agar is extracted from certain red seaweeds, and once it's dried, a small amount of it can set almost any liquid you cook with.6 Chemically, it's a long chain of galactose sugars, but your digestive tract can't break those chains apart, so it acts as fiber rather than as sugar.69 It gels at very low amounts, starting at about 0.2% of the liquid, which is why a little goes such a long way.6

It's sold under several names, including kanten in Japanese markets2 and China grass in Indian grocery stores, and older texts call it Japanese isinglass.6 Agar also has a second life in the laboratory, where microbiologists grow bacteria on plates of it, so if you've searched for "agar" and found petri dishes, that's the same gel doing a very different job.9

Agar comes from the same family of foods as seaweed and sea moss, refined down to the part that gels, so what it brings to your plate is fiber.

A short history of kanten

Red seaweeds have been eaten in Japan since the Nara period, and the gel made from them has been a Japanese food for more than 350 years.4 The first records of agar come from Mino Tarozaemon, who made kanten in the late 1650s or early 1660s,2 and Japanese cooks still use it for clear jellies and for tokoroten, thin noodles pressed from agar jelly, where a typical serving holds about 1 gram of agar.4 Seaweed in general remains part of the everyday Japanese diet, at about 14.2 grams per person per day in one estimate.12

Agar also found its way into medicine. It has been listed as a laxative in the Japanese Pharmacopoeia since 1920,4 and the British Pharmaceutical Codex of 1954 and the U.S. Pharmacopeia of 1960 described it as a mild laxative at 4 to 16 grams a day, working by the way it swells.6 Both uses come from the same property: agar holds water, so it sets a dessert in the dish and adds bulk to what moves through your gut.6

Agar agar powder vs. flakes vs. bars

All three forms are the same gel, and the difference is how concentrated they are and how long they take to dissolve. A level teaspoon of powder weighs about 2.75 grams,6 and in a cup of liquid that works out to a gel of just over 1%, the same strength the official identity test uses to show that agar sets firm.6

For a softer, spoonable set, such as a panna cotta or a pudding, use about half as much. Powder is the form most recipes are written for, so if you're buying only one, start there.

Agar agar nutrition facts

Values for agar powder (Gelidium elegans, item 09049) from the Standard Tables of Food Composition in Japan, eighth revised edition, 2023 supplement; the 2-gram amounts are our calculations from the per-100-gram values.1

The USDA's FoodData Central entry for dried agar (FDC ID 170090) reads very differently. It lists only 7.7 grams of fiber per 100 grams alongside much larger amounts of minerals, such as 770 milligrams of magnesium and 21.4 milligrams of iron, from older analyses, many of them based on only a few samples.11 At a 2-gram serving, even those figures come to about 15 milligrams of magnesium.11

Agar bars, kaku-kanten, are nearly as concentrated as the powder, at 74.1 grams of fiber per 100 grams in Japan's tables.1 With almost no available carbohydrate, agar adds essentially no sugar to a dessert, so the sweetness comes from whatever fruit or honey you add.1

Is agar agar healthy?

Agar's value to your health is its fiber, the gel-forming kind most diets are missing, in a form you can turn into dessert, and that's a gap I want you to close.7 Your body doesn't absorb agar unchanged, your gut bacteria ferment only part of it, and people have taken 4.5 grams a day for 12 weeks without noticeable side effects, as Europe's food-safety agency noted when it re-evaluated agar in 2016.6

The best fiber for you is the one that suits your gut, and I like to fine-tune it to the person. People who bloat easily often do better with gentler fibers, and it's something I see all the time: someone with bloating or gas gets handed a hard-to-digest fiber that doesn't suit them.14 Agar gives you another way in, one you eat as food, and because you decide how much goes into each jelly or bowl of noodles, it's easy to start small and build up. Our guide to how much fiber per day can help you plan the rest.

How agar agar works in your body

Watch a pot of agar cool on the counter and you'll see its whole job. A thin, clear liquid turns into a firm gel that holds water in place, and that same water-holding gel is what agar brings to your digestion. Your own enzymes can't break agar down, so it travels the length of your gut as fiber, and at each stage it does something useful.6

Your gut also adapts to what you feed it, and I've talked on my show about a study that fascinated me when I was writing my first book.16

In that study, researchers found that genes for breaking down the red-seaweed sugars in nori had passed from ocean bacteria into a gut bacterium from Japanese people, and those genes turned up often in Japanese gut samples and not at all in North American ones.12 The same thing happens with any fiber you add: when someone goes from eating almost no fiber to a lot, they get gas at first while the gut adjusts, which is something we see as well.16 Starting with a small serving of agar and building up gives your gut bacteria time to catch up. Learn more about your microbiome and the prebiotics that feed it.

Agar agar benefits

Agar's benefits come from its gel, which holds water, slows your stomach and gives your gut bacteria something to ferment, and in people that has meant more regular bowel movements, more weight lost, and lower blood sugar and cholesterol numbers.3456

Agar agar vs. gelatin (and is it vegan?)

Agar is the usual plant-based swap for gelatin, and it's a good one.2 Gelatin is made mostly from animal skins and bones, and pig skin alone accounted for about 46% of world production in 2011 figures,8 so agar gives you a way to make gummies, marshmallows and set desserts with no question about the animal behind them.

Pork is one food I ask you to leave off your plate, for wisdom as well as for health, and the line in Scripture is clear: "And the swine, though he divide the hoof, and be clovenfooted, yet he cheweth not the cud; he is unclean to you" (Leviticus 11:7).20 The health side is covered in why you should avoid pork. When you want gelatin for its collagen, pick a package that names beef (bovine) or fish as the source, as our guide to beef gelatin explains. The two do different jobs in your diet, since agar brings fiber and gelatin brings collagen protein, so plenty of kitchens keep both.

They also behave differently on the plate. Agar starts to set as it cools to about 38°C (100°F) and won't melt again until it's heated to about 85°C (185°F),6 so an agar jelly holds its shape on a warm table and stays firm in your mouth. Gelatin melts at about 37°C (99°F), close to body temperature, which gives it that soft, melt-on-the-tongue texture.19

To swap agar for gelatin, use agar powder in about equal amounts, boil it in the liquid to dissolve it instead of blooming it, and expect a firmer, cleaner-cutting set. For a softer dessert, start with a little less agar.

Agar vs. carrageenan and other gums

Carrageenan comes from red seaweeds too, but from different species, such as Irish moss (Chondrus crispus), and it was first extracted in 1862.2 It's a different gel with its own chemistry, and our guide to carrageenan explains why it's on the avoid list and names agar agar first among its alternatives. The thickeners you'll see on other ingredient labels, such as guar gum, locust bean gum, gellan gum and xanthan gum, each come from a different source and have their own research, covered on their own pages.

When you're buying packaged jellies, gummies or puddings, my guideline is to buy food with five ingredients or fewer,21 and a homemade agar jelly makes that easy, with puréed fruit, agar and a spoonful of raw honey.

How to use agar agar

The main thing to know about agar is that it needs to boil, because it won't dissolve in cold water.6 Whisk the powder into cold or room-temperature liquid first, bring the pot to a boil and let it simmer, stirring, until no grains remain, which takes a few minutes for powder and 10 to 15 minutes for flakes and bars unless you grind them first. Then pour it into a dish or mold. Because agar sets well above room temperature, it firms up on the counter, often within minutes, and doesn't need the fridge.6 If a jelly comes out too soft or too firm, you can melt it down again, adjust the agar and let it set once more.6

A few tips make it reliable every time:

• Add acidic fruit last. Lemon juice, berries and other tart fruit go in after the agar has dissolved, since long boiling in acid weakens the gel.6

• Sweetening helps the set. Sugars, including the sugars in honey, make an agar gel firmer.6

• Test tricky fruits. Tannic acid in some fruits, including squash, apples and prunes, can keep agar from setting, so with pumpkin or apple desserts, cool a spoonful on a cold plate before you pour, and simmer in a little more agar if it stays soft.6

How to buy and store agar agar

Look for agar agar in health food stores, Indian and Asian grocery stores and the baking aisle near other thickeners, and check the shelf for its other names, kanten, China grass and Japanese gelatin. Choose plain agar with nothing else on the ingredient list, so you decide what goes into your dessert. Keep the dry powder, flakes or bars in a sealed jar in a cool, dry cupboard. Set agar desserts keep a few days, covered, in the refrigerator.

Agar agar recipes

A big part of beating sugar cravings, as I've said on my show, is getting more protein, fiber and water,22 and agar lets you make a sweet treat that brings fiber with it. Fruit and a spoonful of raw honey do the sweetening below, and coconut milk brings the creaminess.

Each of the four servings holds about 1.4 grams of agar, right in the range of a typical portion of jelly.64

Using half the usual amount of agar gives this panna cotta a soft, spoonable set, and the honey works out to about 1½ teaspoons a serving.

More ways to cook with agar:

For more sweet swaps, see vegan candy, and to spot the sugar in store-bought treats, see hidden sugar foods.

Agar agar side effects and safety

• Dry agar and swallowing. Dry agar swells as it takes up water, and the FDA requires dry gum laxatives to warn that taking them without enough fluid can block the throat and cause choking.24 Cook with dissolved agar, and if you ever take it dry, take it with a full glass (8 ounces) of water. With trouble swallowing, a narrowed esophagus or bowel, or a bowel obstruction, skip agar supplements.6

• Very large, concentrated amounts. One woman needed surgery for blockages in her small intestine after eating a large amount of highly concentrated agar,25 so use it the way recipes do, about a teaspoon per cup of liquid.

• After weight-loss surgery. One woman developed an agar mass in her stomach pouch after an agar dessert, 5 years after gastric bypass,26 so ask your surgical team when soft gels fit your diet.

• Bloating or IBS. My advice with gut symptoms is to go low and slow with fiber and give your microbiome time to adjust.27 Begin with half a serving and drink water through the day.

• Pregnancy and children. Agar in desserts and soups is an everyday food. European medicines guidance on agar-containing medicines says they can be used in pregnancy and breastfeeding if medically needed and doesn't provide for them in children, so keep to food amounts.6

• Signs to stop. If you have chest pain, vomiting, or trouble swallowing or breathing after taking dry agar, get medical care right away.24 Stop eating agar if you notice hives, itching or swelling, since allergic reactions to agar have been reported.28

The bottom line

Agar agar: frequently asked questions

References

1. Ministry of Education, Culture, Sports, Science and Technology (Japan). Standard Tables of Food Composition in Japan, 8th revised edition, 2023 supplement: Tengusa, agar-agar powder (09049); agar-agar bars, kaku-kanten (09027); agar jelly (09028). Food Composition Database. Accessed 2026-11-06.
2. Mendes M, Cotas J, Pacheco D, Ihle K, Hillinger A, Cascais M, et al. Red Seaweed (Rhodophyta) Phycocolloids: A Road from the Species to the Industry Application. Mar Drugs. 2024;22(10):432. doi:10.3390/md22100432. PMID:39452840
3. Sanaka M, Yamamoto T, Anjiki H, Nagasawa K, Kuyama Y. Effects of agar and pectin on gastric emptying and post-prandial glycaemic profiles in healthy human volunteers. Clin Exp Pharmacol Physiol. 2007;34(11):1151-5. doi:10.1111/j.1440-1681.2007.04706.x. PMID:17880369
4. Hara H, Taki C, Kon R, Uzuhashi Y, Sasaya M, Sasaki K. Effects of agar administration on the defecation and fecal condition of healthy volunteers. Jpn J Nutr Diet (Eiyogaku Zasshi). 2000;58(6):239-248. doi:10.5264/eiyogakuzashi.58.239
5. Maeda H, Yamamoto R, Hirao K, Tochikubo O. Effects of agar (kanten) diet on obese patients with impaired glucose tolerance and type 2 diabetes. Diabetes Obes Metab. 2005;7(1):40-6. doi:10.1111/j.1463-1326.2004.00370.x. PMID:15642074
6. EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS), Mortensen A, Aguilar F, Crebelli R, Di Domenico A, Frutos MJ, et al. Re-evaluation of agar (E 406) as a food additive. EFSA J. 2016;14(12):e04645. doi:10.2903/j.efsa.2016.4645. PMID:42006017
7. Axe J. The Toxin Nobody Checks For (It's in Your Clothes & Bed) | Alex Clark. The Dr. Josh Axe Show. 2026.
8. Said NS, Sarbon NM. Physical and Mechanical Characteristics of Gelatin-Based Films as a Potential Food Packaging Material: A Review. Membranes (Basel). 2022;12(5):442. doi:10.3390/membranes12050442. PMID:35629768
9. Watanabe M, Risi R, Masi D, Caputi A, Balena A, Rossini G, et al. Current Evidence to Propose Different Food Supplements for Weight Loss: A Comprehensive Review. Nutrients. 2020;12(9):2873. doi:10.3390/nu12092873. PMID:32962190
10. Enoki T, Okuda S, Kudo Y, Takashima F, Sagawa H, Kato I. Oligosaccharides from agar inhibit pro-inflammatory mediator release by inducing heme oxygenase 1. Biosci Biotechnol Biochem. 2010;74(4):766-70. doi:10.1271/bbb.90803. PMID:20378994
11. US Department of Agriculture, Agricultural Research Service. FoodData Central, SR Legacy: Seaweed, agar, dried. FDC ID 170090 (NDB 11663). Accessed 2026-11-06.
12. Hehemann JH, Correc G, Barbeyron T, Helbert W, Czjzek M, Michel G. Transfer of carbohydrate-active enzymes from marine bacteria to Japanese gut microbiota. Nature. 2010;464(7290):908-12. doi:10.1038/nature08937. PMID:20376150
13. US Food and Drug Administration. 21 CFR 184.1115, Agar-agar (direct food substances affirmed as generally recognized as safe). Electronic Code of Federal Regulations. Accessed 2026-11-06.
14. Axe J. Complete Guide to Healing Leaky Gut Naturally. The Dr. Josh Axe Show. 2026, at 41:21 and 42:03.
15. Clegg ME, Shafat A. The effect of agar jelly on energy expenditure, appetite, gastric emptying and glycaemic response. Eur J Nutr. 2014;53(2):533-9. doi:10.1007/s00394-013-0559-x. PMID:23872837
16. Axe J, Petrucci K. The Real Reason Your Gut Won't Heal (And How Bone Broth Fixes It). The Dr. Josh Axe Show. 2026, at 25:30, 25:37 and 25:53.
17. Axe J. Healthy Weight & Metabolic Reset: The 90-Day Healing Protocol. DrAxe.com. 2026. "Top 8 metabolic boosters" (psyllium or glucomannan, 3–5 g before meals) and "What your metabolism runs on" (fiber, 30 g+).
18. Ramnani P, Chitarrari R, Tuohy K, Grant J, Hotchkiss S, Philp K, et al. In vitro fermentation and prebiotic potential of novel low molecular weight polysaccharides derived from agar and alginate seaweeds. Anaerobe. 2012;18(1):1-6. doi:10.1016/j.anaerobe.2011.08.003. PMID:21924371
19. Russo Spena S, Pasquino R, Grizzuti N. K-Carrageenan/Locust Bean Gum Gels for Food Applications-A Critical Study on Potential Alternatives to Animal-Based Gelatin. Foods. 2024;13(16):2575. doi:10.3390/foods13162575. PMID:39200501
20. The Holy Bible, King James Version. Leviticus 11:7.
21. Axe J, Rubin J. The Biblio Diet. Hachette Book Group; 2025. ISBN 9781546008439 (ebook p. 43, five-ingredient guideline).
22. Axe J. Heavy Metals, Sugar Cravings, & Natural Flavors | Q&A. The Dr. Josh Axe Show. 2024.
23. Gin H, Orgerie MB, Aubertin J. The influence of Guar gum on absorption of metformin from the gut in healthy volunteers. Horm Metab Res. 1989;21(2):81-3. doi:10.1055/s-2007-1009156. PMID:2722133
24. US Food and Drug Administration. 21 CFR 201.319, Water-soluble gums, hydrophilic gums, and hydrophilic mucilloids (including agar) as active ingredients; required warnings and directions. Electronic Code of Federal Regulations. Accessed 2026-11-06.
25. Osada T, Shibuya T, Kodani T, Beppu K, Sakamoto N, Nagahara A, et al. Obstructing small bowel bezoars due to an agar diet: diagnosis using double balloon enteroscopy. Intern Med. 2008;47(7):617-20. doi:10.2169/internalmedicine.47.0520. PMID:18379147
26. Gero D, Chosidow D, Marmuse JP. An unusual cause of solid food intolerance and gastric pouch dilation 5 years after Roux-en-Y gastric bypass: agar-agar bezoar. Surg Obes Relat Dis. 2015;11(5):1184-5. doi:10.1016/j.soard.2015.05.010. PMID:26077699
27. Axe J, Cole W. Heal Your Cells. Avery; 2026. ISBN 9798217181353. "What to Do, Starting Now," Step 1 (start low and slow with fiber).
28. Criep LH, Riley WK. Allergic manifestations to agar. J Am Med Assoc. 1951;145(7):485-6. doi:10.1001/jama.1951.72920250005008c. PMID:14794472
29. Melnick RL, Huff J, Haseman JK, Dieter MP, Grieshaber CK, Wyand DS, et al. Chronic effects of agar, guar gum, gum arabic, locust-bean gum, or tara gum in F344 rats and B6C3F1 mice. Food Chem Toxicol. 1983;21(3):305-11. doi:10.1016/0278-6915(83)90065-0. PMID:6683227
30. Glauert HP, Bennink MR, Sander CH. Enhancement of 1,2-dimethylhydrazine-induced colon carcinogenesis in mice by dietary agar. Food Cosmet Toxicol. 1981;19(3):281-6. doi:10.1016/0015-6264(81)90385-0. PMID:6266936
31. Jacobs LR. Relationship between dietary fiber and cancer: metabolic, physiologic, and cellular mechanisms. Proc Soc Exp Biol Med. 1986;183(3):299-310. doi:10.3181/00379727-183-42423. PMID:3025886

Dr. Josh Axe, DC, DNM, CNS

Doctor of Natural Medicine · Founder, DrAxe.com

Dr. Axe is a certified doctor of natural medicine, clinical nutritionist, and multiple New York Times bestselling author. He has spent 20+ years in clinical practice helping people heal at the root cause and founded one of the most-visited natural-health platforms in the world.

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This article is for educational purposes. See our medical disclaimer.