What does Polyglutamic Acid do?#
A leave-on serum with polyglutamic acid, a water-holding ingredient made by fermenting soybeans — it is the sticky part of natto. It helps skin look and feel hydrated.
Benefits
- Holds water at the surface, so skin feels more comfortable and looks less dry
- Dries down to a light, flexible film that sits well under a moisturiser
- Gentle enough for morning and night
- Goes on best straight after cleansing, while skin is still damp
How it works
Polyglutamic acid is made by fermenting soybeans with the same bacteria that make natto, and it is a large molecule rather than an acid. On skin it works as a humectant — it holds water where it is applied and dries down to a thin, flexible film. Because it stays on the surface, what it changes is how hydrated skin looks and feels, and that shows from the first use rather than building over weeks.
How to use Polyglutamic Acid#
Before you start
It is the same substance as the sticky part of natto, fermented soybeans. Anyone allergic to natto or fermented soy should skip it.
Where it goes
A serum or essence goes on after cleansing and before your moisturiser; a cream carrying it simply takes the moisturiser's own place. Morning and night alike.
Where to apply
All over the face. Keep it out of the eye itself, as with any leave-on.
How to apply
A thin layer onto damp skin. It holds water rather than sealing it in, so something richer over the top gives it more to hold on to.
Alongside others
Give an acid or a vitamin C step a moment to settle before layering this over it — the film sets up better on skin that is no longer wet.
What to expect
A difference in how hydrated skin feels from the first use, and no break-in phase — a humectant has no purge or peeling stage to work through. Any product can still disagree with an individual skin, so bring it in on its own.
What to look for
Despite the name it is not an exfoliating acid. It is a large fermented molecule, and it does not behave the way glycolic or salicylic acid does.
If it doesn't suit
If it feels tacky, or the product you apply next balls up, use less. If this or anything else in your routine stings, pause that product, let skin settle, and reintroduce it on its own.
Do not use if you are allergic to natto or fermented soy — polyglutamic acid is the same substance. Stop use if unexpected discomfort occurs, and consult a healthcare professional if it does not settle.
The form you will see it in
Polyglutamic acid hydrating serum
- Where it goes
- Before moisturizer
Using Polyglutamic Acid with other ingredients
What not to use with Polyglutamic Acid
Nothing flagged. None of the ingredients this wiki covers needs to be kept apart from Polyglutamic Acid — check the label of anything not covered here.
Who should avoid Polyglutamic Acid?#
Six situations change whether Polyglutamic Acid suits your skin right now. Each one is either a reason to skip it, a reason to go slowly, or nothing to watch for.
- Fragile or Sensitive
- Go slowly
- Maternity & Nursing
- No caution
- Recent Facial or Laser
- No caution
- Prone to Redness
- No caution
- Dry or Itchy Patches
- No caution
- Recent Shave or Wax
- No caution
Fragile or Sensitive — Use it less often — or stop — if it feels uncomfortable, and keep it off skin that’s broken, cut or sunburned.
Cosmetic strength limits for Polyglutamic Acid where you live#
| Region | Most a cosmetic may contain | |
|---|---|---|
 United States | No explicit cap | |
The FDA restricts a short list of ingredients and sets no general strength ceiling on the rest. A figure marked "guidance, not law" is the Cosmetic Ingredient Review panel's recommendation. 21 CFR part 700, subpart B — Requirements for Specific Cosmetic Products (FDA) | ||
 Canada | No explicit cap | |
One list does the work — Health Canada's Hotlist of prohibited and restricted cosmetic ingredients. | ||
 European Union | No explicit cap | |
The Cosmetics Regulation's annexes, consolidated to 1 May 2026. A figure marked "guidance, not law" comes from the EU's cosmetic safety committee rather than from the annexes. | ||
 Great Britain | No explicit cap | |
Great Britain kept the annexes as its own law and updates them only when it chooses; Northern Ireland follows the live EU Regulation, which is why some rows read differently for each. Regulation (EC) No 1223/2009 as it applies in Great Britain · Regulation (EC) No 1223/2009, Annexes II–VI | ||
 India | No explicit cap | |
India writes its own standard, aligned to the European rules as they stood in 2012. Mandatory since 9 February 2026. IS 4707 (Part 2):2025 — restricted and prohibited cosmetic ingredients · IS 4707 (Part 3):2025 — preservatives · Cosmetics Rules, 2020, Ninth Schedule | ||
 Brazil | No explicit cap | |
ANVISA rewrote its restricted list in June 2026, and a companion act amended the prohibited list at the same time. RDC 1.029/2026 — restricted ingredients · RDC 529/2021 — prohibited ingredients, as amended by RDC 1.030/2026 · RDC 528/2021 — preservatives | ||
 Japan | No explicit cap | |
Japan's cosmetics standard keeps drug ingredients out of cosmetics, so most of its figures sit in the ministry's list of the ones a cosmetic may still contain. Cosmetics Standards (化粧品基準), Ministry of Health, Labour and Welfare · Cosmetics Standards — the ministry's own English translation · Drug ingredients permitted in cosmetics — 2007 notification | ||
 South Korea | No explicit cap | |
One MFDS regulation carries both the prohibited list and the restricted list, in force 18 March 2026. Sunscreens and a few other categories are cleared product by product instead. Regulation on Safety Standards for Cosmetics (MFDS Notification 2026-19) · Regulation on the Review of Functional Cosmetics (MFDS Notification 2025-88) | ||
 Kenya | No explicit cap | |
Kenya's standard applies the EU annexes as they stand rather than copying them, so its ingredient limits are the EU's — including the 2024 additions. A figure marked "guidance, not law" sits outside the annexes and does not carry over. KS EAS 377-1, -2 and -3:2022 — cosmetics safety requirements, published by KEBS · Regulation (EC) No 1223/2009, Annexes II–VI | ||
 Namibia | No explicit cap | |
Namibia sets no ingredient limits at all. Its cosmetic rule is a single line requiring a product to be free of any harmful ingredient. Foodstuffs, Cosmetics and Disinfectants Ordinance 18 of 1979, and the regulations under it | ||
 Ukraine | No explicit cap | |
Ukraine's own transposition of the EU annexes, as they stood before the 2024 additions, fully in force since 3 August 2026. A further revision is due on 1 February 2027. Technical Regulation on cosmetic products — Cabinet Resolution No. 65 of 20 January 2021 | ||
 Georgia | No explicit cap | |
Georgia has no cosmetics rulebook — its register of technical regulations carries no cosmetics entry — so only the general product-safety duty applies. | ||
 Australia | No explicit cap | |
Australia writes no cosmetic ingredient list. A figure here is the point at which a substance becomes a medicine or a scheduled substance carrying Caution labelling, so its numbers sit well above other markets'. Poisons Standard — June 2026 · Therapeutic Goods (Excluded Goods) Determination 2018 | ||
 United Arab Emirates | No explicit cap | |
The Gulf standard points at the EU annexes as amended, so its ingredient limits are the EU's. A figure marked "guidance, not law" sits outside the annexes and does not carry over. GSO 1943:2024 — Cosmetic products: safety requirements (Gulf technical regulation) · Regulation (EC) No 1223/2009, Annexes II–VI | ||
 Kuwait | No explicit cap | |
The Gulf standard points at the EU annexes as amended, so its ingredient limits are the EU's. A figure marked "guidance, not law" sits outside the annexes and does not carry over. GSO 1943:2024 — Cosmetic products: safety requirements (Gulf technical regulation) · Regulation (EC) No 1223/2009, Annexes II–VI | ||
 Hong Kong | No explicit cap | |
Hong Kong writes no cosmetics rulebook. Its Poisons List (Cap. 138A, Schedule 10) decides which substances may be sold only as medicines, and general safety is judged case by case against whichever overseas standard the enforcer considers reasonable. Pharmacy and Poisons Regulations (Cap. 138A), Schedule 10 — the poisons list · Pharmacy and Poisons Board — Guidance Notes on classifying pharmaceutical products, April 2026 | ||
 Singapore | No explicit cap | |
Singapore writes the ASEAN annexes into its own schedule, and its regulator tells companies to check the current ASEAN release as well — which is why a figure here can read "guidance, not law". Health Products (Cosmetic Products — ASEAN Cosmetic Directive) Regulations 2007, Third Schedule · ASEAN Cosmetic Directive annexes — release 2026-1, 22 June 2026 | ||
 Brunei | No explicit cap | |
Brunei carries the 2007 ASEAN annexes in its own schedule and has not updated them since, so it reads differently from Singapore on several ingredients. Medicines (Cosmetic Products) Regulations (Cap. 285 Rg 1), Schedule 1 — revised edition 2024 | ||
 Jordan | No explicit cap | |
Jordan's cosmetic rules defer to "the approved references" and name none of them, so there is no Jordanian figure to read. The only number in the instrument governs the ingredient list on the pack. JFDA instructions on cosmetics and pharmaceutical cosmetics, 2026 | ||
 Trinidad & Tobago | No explicit cap | |
Trinidad and Tobago has had the power to set cosmetic standards since 1960 and has never used it. The regulations made under the Act cover food and drugs, with no cosmetics part; what binds is the Act's general rule against selling a cosmetic that may injure the user. Food and Drugs Act, Chap. 30:01 · Food and Drugs Regulations | ||
No cosmetic regulator in the 20 markets above sets a maximum strength for polyglutamic acid. That is the state of the rules, not a signal to use more: how much goes into a product is the formulator's decision.
Open a market to see the rulebook its figure comes from. Those notes describe each market's own rules as we read them, current to August 24, 2026; the linked documents are the authority, and nothing here is legal advice.
Common questions about Polyglutamic Acid#
When should you apply Polyglutamic Acid?
- Morning or evening.
How often can you use Polyglutamic Acid?
- Daily.
Where do you apply Polyglutamic Acid?
- All over the face. Keep it away from your eyes and lips.
Does Polyglutamic Acid make skin more sensitive to the sun?
- No. Polyglutamic Acid is not flagged as increasing sun sensitivity.
What should you not use with Polyglutamic Acid?
- Nothing flagged. None of the ingredients this wiki covers needs to be kept apart from Polyglutamic Acid — check the label of anything not covered here.
Who should avoid Polyglutamic Acid?
- Go slowly with Fragile or Sensitive.
Is there a cosmetic limit for Polyglutamic Acid?
- No. No cosmetic regulator in the United States, Canada, the European Union or Great Britain sets a maximum strength for it. That is a limit on the rules, not a signal to use more.
Related ingredients#
How we check this#
Everything on this page traces to the sources listed below — regulators' own publications and published studies. Where the evidence does not answer a question, it is left unanswered.
Some sources below are medical studies. This ingredient has been studied in conditions a doctor treats, and the record cited here includes findings that did not favour it. We use those studies for their safety and handling detail only. A cosmetic product is not a medicine and is not intended to treat, cure or prevent any condition.
Some sources below are the official product information for prescription medicines — some contain this ingredient at higher strengths, others are cited for how they interact with it. We use them for their safety and handling detail only. A cosmetic product is not one of those medicines and is not intended to treat any condition.
Our review is AI-assisted and is not a named expert's opinion. Last reviewed September 2, 2026.
Think something here is out of date or wrong? Email us at wiki@skinintelligence.ai with your reasoning and where you read it. We read what people send, and we update the page when the sources support it.
Regulators and official bodies · 13
- S14CosIng — ingredient record POLYGLUTAMIC ACID, INCI name Polyglutamic Acid, CAS 25513-46-6, description "Polymer of glutamic acid", function SKIN CONDITIONING, no Cosmetics Regulation provisions, no SCCS opinion. European Commission.
- S15CosIng — ingredient record SODIUM POLYGLUTAMATE, CAS 28829-38-1, description "Glutamic Acid Homopolymer Sodium Salt", functions HAIR CONDITIONING / HUMECTANT / SKIN CONDITIONING, no Cosmetics Regulation provisions, no SCCS opinion. European Commission.
- S16Regulation (EC) No 1223/2009 of the European Parliament and of the Council of 30 November 2009 on cosmetic products (recast), consolidated text 02009R1223 as at 2025-09-01, Annexes II–VI.
- S17Regulation (EC) No 1223/2009 on cosmetic products as retained in Great Britain, legislation.gov.uk, Annexes II–VIII.
- S18Health Canada, Cosmetic Ingredient Hotlist: Prohibited and Restricted Ingredients — the administrative tool applied under the Food and Drugs Act and the Cosmetic Regulations.
- S19US FDA, Prohibited & Restricted Ingredients in Cosmetics (21 CFR Part 700, Subpart B).
- S20Roaccutane 20 mg soft capsules — Summary of Product Characteristics, emc product 100634 (§4.3 Contraindications, §4.4 Special warnings, §4.5 Interactions, §4.6 Pregnancy and lactation).
- S21Adapalene/Benzoyl Peroxide 0.1%/2.5% gel — Summary of Product Characteristics, emc product 15922 (§4.2, §4.4, §4.5).
- S22Lymecycline 408 mg Capsules, hard — Summary of Product Characteristics. electronic Medicines Compendium, product 101121.
- S26Health Canada. Cosmetic Ingredient Hotlist — list of prohibited and restricted cosmetic ingredients. No entry for polyglutamic acid or sodium polyglutamate.
- S2721 CFR Part 700 — General (Cosmetics), eCFR current edition; §§700.11–700.35. No entry for polyglutamic acid.
- S28Regulation (EC) No 1223/2009 of the European Parliament and of the Council of 30 November 2009 on cosmetic products (recast), as retained in UK law.
- S35Differin Gel — Summary of Product Characteristics, §§4.4 and 4.5. electronic Medicines Compendium, product 921.
Studies and references · 27
- S1Ko HJ, Park S, Shin E, Kim J, Lee GS, Lee YJ, Park SM, Lee J, Hyun CG. "Poly-γ-Glutamic Acid from a Novel Bacillus subtilis Strain: Strengthening the Skin Barrier and Improving Moisture Retention in Keratinocytes and a Reconstructed Skin Model." Int J Mol Sci 2025;26(3):983. PMID 39940752. DOI 10.3390/ijms26030983.
- S2Serra M, Gudina E, Botelho C, Teixeira JA, Barros AN. "Polyglutamate: Unleashing the Versatility of a Biopolymer for Cosmetic Industry Applications." Cosmetics. 2024;11(3):76. DOI 10.3390/cosmetics11030076. Use with care — a large share of its cosmetic claims rest on patents and on brand/supplier marketing data reproduced verbatim.
- S3Parati M, Philip C, Allinson SL, Mendrek B, Khalil I, Tchuenbou-Magaia F, Kowalczuk M, Adamus G, Radecka I. "Brown Algae as a Valuable Substrate for the Cost-Effective Production of Poly-γ-Glutamic Acid for Applications in Cream Formulations." Polymers 2024;16(14):2091. PMID 39065408. DOI 10.3390/polym16142091.
- S4Elbanna K, Alsulami FS, Neyaz LA, Abulreesh HH. "Poly (γ) glutamic acid: a unique microbial biopolymer with diverse commercial applicability." Front Microbiol 2024;15:1348411. PMID 38414762. DOI 10.3389/fmicb.2024.1348411.
- S5Ogunleye A, Bhat A, Irorere VU, Hill D, Williams C, Radecka I. "Poly-γ-glutamic acid: production, properties and applications." Microbiology 2015;161(1):1–17. DOI 10.1099/mic.0.081448-0.
- S6Liu X, Liu F, Liu S, Li H, Ling P, Zhu X. "Poly-γ-glutamate from Bacillus subtilis inhibits tyrosinase activity and melanogenesis." Appl Microbiol Biotechnol. 2013. DOI 10.1007/s00253-013-5254-6. (Abstract only in vault — full text paywalled; author line verified via Crossref.).
- S7Lee NR, Go TH, Lee SM, Jeong SY, Park GT, Hong CO, Son HJ. "In vitro evaluation of new functional properties of poly-γ-glutamic acid produced by Bacillus subtilis D7." Saudi J Biol Sci 2014. PMID 24600308. DOI 10.1016/j.sjbs.2013.09.004.
- S8Li C, Ma H, Li P, Zhang S, Xu J, Wang L, Sheng W, Xu T, Shen L, Wang W, Xia T. "Cucumber (Cucumis sativus L.) with heterologous poly-γ-glutamic acid has skin moisturizing, whitening and anti-wrinkle effects." Int J Biol Macromol 2024;262(Pt 1):130026. PMID 38336313. DOI 10.1016/j.ijbiomac.2024.130026. Material is a transgenic-plant extract, not pure γ-PGA — flagged as ambiguous..
- S9Choi JC, Uyama H, Lee CH, Sung MH. "Promotion Effects of Ultra-High Molecular Weight Poly-γ-Glutamic Acid on Wound Healing." J Microbiol Biotechnol. 2015 Jun;25(6):941-5. PMID 25791849.
- S10Poo H, Park C, Kwak MS, Choi DY, Hong SP, Lee IH, Lim YT, Choi YK, Bae SR, Uyama H, Kim CJ, Sung MH. "New biological functions and applications of high-molecular-mass poly-gamma-glutamic acid." Chem Biodivers 2010;7(6):1555–62. PMID 20564573. DOI 10.1002/cbdv.200900283.
- S11Inomata N, Nomura Y, Ikezawa Z. "Involvement of poly (γ-glutamic acid) as an allergen in late-onset anaphylaxis due to fermented soybeans (natto)." J Dermatol 2012. PMID 22035089. DOI 10.1111/j.1346-8138.2011.01282.x.
- S12Suzuki K, Futamura K, Sato N, Nakamura M, Matsunaga K, Yagami A. "Two cases of fermented soybean (natto) allergy diagnosed using the skin prick test and enzyme linked immunosorbent assay for poly-γ-glutamic acid." J Dermatol 2020. PMID 32892385. DOI 10.1111/1346-8138.15601.
- S13Shigeno A, Suzuki T, Obayashi M, Asada K, Matsushima S. "Natto (fermented soybeans)-induced anaphylaxis in a surfer with the possibility of sensitization to poly(γ-glutamic acid) from cutaneous exposure to jellyfish sting: a case report." Int J Emerg Med 2024. PMID 38500076. DOI 10.1186/s12245-024-00617-1.
- S23"Polyglutamic Acid: A Novel Peptide for Skin Care." Cosmetics & Toiletries. Cited without authors — the byline could not be confirmed from the page itself. The primary work it reports is attributed in the peer-reviewed literature as Ben-Zur N., Goldman D. M. (2007) Cosmetics & Toiletries 122:65–74, per the reference list of S5.
- S24Nikolis A, Nestor MS, Czuwara J, Depfenhart M, Fluhr JW, Addor FASA, Piotrowski K, Zielinski Y, Lachmann N, Prygova I, Berlin I, Pellacani G. "Concomitant Use of Dermo-Cosmetic Skin Care in Aesthetic Procedures: Systematic Review with Expert Panel Recommendations." Clin Cosmet Investig Dermatol 2026. PMID 41773167. DOI 10.2147/CCID.S577128.
- S25"Pilot Clinical Safety and Efficacy Evaluation of a Topical 3% Tranexamic Acid Cream and Serum Protocol for Managing Facial Hyperpigmentation in Caucasian Patients." Cosmetics 2024;11(5):168. Cited without authors — byline not confirmed against a PMID/DOI record. Used only for its published INCI list, in which Sodium Polyglutamate is co-formulated with tranexamic acid, niacinamide and hyaluronates.
- S29Ko HJ, Park S, Shin E, Kim J, Lee GS, Lee YJ, Park SM, Lee J, Hyun CG. "Poly-γ-Glutamic Acid from a Novel Bacillus subtilis Strain: Strengthening the Skin Barrier and Improving Moisture Retention in Keratinocytes and a Reconstructed Skin Model." Int J Mol Sci. 2025 Jan 24. PMID 39940752; PMC11817278.
- S30Parati M, Philip C, Allinson SL, Mendrek B, Khalil I, Tchuenbou-Magaia F, Kowalczuk M, Adamus G, Radecka I. "Brown Algae as a Valuable Substrate for the Cost-Effective Production of Poly-γ-Glutamic Acid for Applications in Cream Formulations." Polymers (Basel). 2024 Jul 22. PMID 39065408; PMC11281067.
- S31Lee NR, Go TH, Lee SM, Jeong SY, Park GT, Hong CO, Son HJ. "In vitro evaluation of new functional properties of poly-γ-glutamic acid produced by Bacillus subtilis D7." Saudi J Biol Sci. 2014 Apr. PMID 24600308; PMC3942858.
- S32Elbanna K, Alsulami FS, Neyaz LA, Abulreesh HH. "Poly (γ) glutamic acid: a unique microbial biopolymer with diverse commercial applicability." Front Microbiol. 2024. PMID 38414762; PMC10897055.
- S33Shigeno A, Suzuki T, Obayashi M, Asada K, Matsushima S. "Natto (fermented soybeans)-induced anaphylaxis in a surfer with the possibility of sensitization to poly(γ-glutamic acid) from cutaneous exposure to jellyfish sting: a case report." Int J Emerg Med. 2024 Mar 18. PMID 38500076; PMC10946159.
- S34Inomata N, Miyakawa M, Aihara M. "Surfing as a risk factor for sensitization to poly(γ-glutamic acid) in fermented soybeans, natto, allergy." Allergol Int. 2018 Jul;67(3):341-346. PMID 29175280.
- S36Chiu YH, Wu YW, Hung JI, Chen MC. "Epigallocatechin gallate/L-ascorbic acid-loaded poly-γ-glutamate microneedles with antioxidant, anti-inflammatory, and immunomodulatory effects for the treatment of atopic dermatitis." Acta Biomater. 2021 Aug;130:223-233. PMID 34087444.
- S37Lee SW, Park HJ, Park SH, Hong S. "Oral administration of poly-γ-glutamic acid prevents the development of atopic dermatitis in NC/Nga mice." Exp Dermatol. 2013 Aug. PMID 23879818.
- S38Chen MC, Chen CS, Wu YW, Yang YY. "Poly-γ-Glutamate microneedles as transdermal immunomodulators for ameliorating atopic dermatitis-like skin lesions in Nc/Nga mice." Acta Biomater. 2020 Sep 15. PMID 32688089.
- S39Srisuwatchari W, Norchai P. "Hypersensitivity reactions associated with nutraceuticals and dietary supplements: A narrative review." Asian Pac J Allergy Immunol. 2026 Jun;44(2):283-296. PMID 42437383.
- S40Chen M, Chen L, Yuan D, Niu L, Hu J, Zhang X, Zhang X, Zhang Y, Zhang X, Ling P, Liu F, Zhang D. "Preparation, function, and safety evaluation of a novel degradable dermal filler, the cross-linked poly-γ-glutamic acid hydrogel particles." J Biomed Mater Res B Appl Biomater. 2023 Jul. PMID 36930047.
