Ingredient Science Guide
Adipic Acid
A Food-Grade Dicarboxylic Acid Used as a pH Regulator and Acidulant in Supplement Formulations
Adipic acid (E355; hexanedioic acid; HOOC-(CH₂)₄-COOH; C₆H₁₀O₄) is a dicarboxylic acid found naturally in small amounts in beets and other plants. Most commercial adipic acid is manufactured industrially, primarily for nylon production, but it has long-established applications in food and supplement formulations as a pH regulator and acidulant.
Compared to stronger acids like citric or tartaric acid, adipic acid has a milder acidity and notably low hygroscopicity, meaning it does not readily absorb moisture from the air. This keeps dry formulations free-flowing and reduces clumping during manufacturing. In Wellness Extract's H2 Molecular Hydrogen Tablets, it contributes to the acid-base effervescent system alongside malic acid, L-tartaric acid, and elemental magnesium.
What It Is
What Is Adipic Acid?
Adipic acid (hexanedioic acid; HOOC-(CH₂)₄-COOH) is a dicarboxylic acid with the chemical formula C₆H₁₀O₄. It occurs naturally in small amounts in some plants, including beets, and is commercially manufactured primarily for nylon production; it is one of the most widely produced industrial chemicals. In food and supplement applications, it is recognized as E355 (EU) and is included on the FDA's list of substances generally recognized as safe for food use under 21 CFR 184.1009.
Adipic acid's key formulation properties are its mild acidity (milder than citric or tartaric acid) and its low hygroscopicity; it does not readily pull moisture from the air. This combination makes it particularly useful in dry powder formulations, effervescent tablets, and gummies where powder flow, stability, and taste balance matter.
E355
Recognized Food Additive: FDA 21 CFR 184.1009 and EU E355
Adipic acid is approved as a food additive for use as a pH control agent, leavening agent, and flavoring/adjuvant. It is on the FDA's list of substances with GRAS status for food use. Its use in dietary supplement tablets is consistent with these established food-additive applications.
Low Hygroscopic
Low Hygroscopicity: Stays Free-Flowing in Powder Formulations
Unlike citric acid, which is highly hygroscopic and readily absorbs moisture (causing powder clumping), adipic acid has low hygroscopicity. This property makes it useful in dry supplement powders and effervescent tablet formulations where maintaining powder flow and preventing moisture-related degradation during manufacturing and storage matters.
Adipic Acid at a Glance
Reference Sheet
IUPAC NameHexanedioic acid
Chemical FormulaC₆H₁₀O₄ (MW 146.14 g/mol)
E NumberE355 (Acidulant / pH Regulator)
FDA Status21 CFR 184.1009; food use GRAS
Natural OccurrenceBeets, some vegetables (small amounts)
Key PropertyLow hygroscopicity; stays free-flowing in powders
AcidityMilder than citric or tartaric acid
WE Product RolepH regulator / acidulant in H2 Molecular Hydrogen Tablets
Effervescence
Mild Acidity Contributes to Effervescent Chemistry
When combined with an alkaline ingredient like sodium bicarbonate or elemental magnesium, adipic acid reacts to produce carbon dioxide (or in the case of magnesium, contributes to accelerating hydrogen gas release). This acid-base reaction is the basis for the effervescence in tablets that fizz when dropped in water.
How It Works
How Adipic Acid Functions in Supplement Formulations
Adipic acid's role is functional and formulation-based rather than pharmacological. It controls pH, maintains powder integrity, and contributes to effervescent chemistry.
pH Control
Acts as an Acidulant to Control Formulation Acidity
Adipic acid donates protons in solution, lowering pH in the formulation's microenvironment. This controlled acidity can help stabilize other ingredients, adjust taste, and contribute to the acid-base reactions that drive tablet effervescence.[1]
Effervescence
Participates in Acid-Base Reaction to Generate Gas and Aid Dissolution
When adipic acid contacts an alkaline ingredient (magnesium, sodium bicarbonate) in water, an acid-base reaction occurs. In H2 tablets, the acidic environment created by adipic acid, malic acid, and tartaric acid accelerates the elemental magnesium-water reaction, generating molecular hydrogen and supporting rapid tablet dissolution.[2]
Powder Flow
Low Hygroscopicity Prevents Moisture Absorption and Clumping
Adipic acid does not readily absorb atmospheric moisture, unlike citric acid (which is notably hygroscopic). This keeps the powder free-flowing during manufacturing and helps maintain tablet integrity and consistency during shelf storage. It is one of the reasons adipic acid is selected for dry powder and effervescent tablet formulations over other acidulants.[1]
Taste
Mild, Smooth Tartness Without Sharp Acidity
Compared to citric acid (sharper) and tartaric acid (aggressive), adipic acid has a mild, smooth tartness that lingers on the palate. In flavored supplement formats like gummies and chewable tablets, this can improve the product's taste profile by providing sourness without overpowering other flavors.
Evidence Summary
What the Evidence Shows for Adipic Acid in Formulations
Adipic acid's role is established as a food-additive and formulation ingredient. The evidence base is regulatory and formulation-based rather than from clinical health trials.
Regulatory
FDA and EU Regulatory Approval as a Food-Grade Acidulant
Functional and regulatory evidence
Regulatory / Functional EvidenceAdipic acid is recognized in U.S. food regulations under 21 CFR 184.1009 and listed by JECFA and Codex as an acidity regulator. FDA classifies it as GRAS for use as a pH control agent and flavor enhancer. The EU designates it E355. This regulatory recognition is itself evidence for its established safety and formulation utility at food-use levels.[1]
Effervescent Formulation
Adipic Acid Used in Hydrogen-Generating Effervescent Tablet Research
Formulation technology evidence
Formulation Research; PMID 34959728A published study on hydrogen-generating effervescent tablets (Rösch et al., Pharmaceuticals, 2021) evaluated different excipients during formulation optimization and selected adipic acid based on its regulatory acceptability and functional properties in this type of tablet system.[2]
Dosage & Forms
Adipic Acid in Supplements: Form and Dose
Adipic acid in supplement products is a formulation ingredient, an acidulant or pH regulator, rather than an active ingredient with a separate recommended daily dose.
As a Supplement Excipient
Adipic Acid as a Formulation Ingredient
| Attribute | Detail |
|---|---|
| Role | Formulation acidulant and pH regulator |
| Products | Effervescent tablets, gummies, supplement powders |
| Typical amount | Product-specific; check label for per-tablet inclusion |
| H2 Tablet use | Contributes to acid-base reaction that drives H₂ release |
Adipic acid at food-additive levels is safe for consumption per regulatory review. It is not intended as an active ingredient with its own therapeutic effect.
Comparisons
Adipic Acid vs. Other Common Supplement Acidulants
Each acidulant has distinct properties that make it suitable for different formulation needs.
| Acidulant | Properties |
|---|---|
| Citric acid | Stronger acidity; highly hygroscopic; more likely to absorb moisture |
| Malic acid | Smooth, prolonged tartness; moderate hygroscopicity |
| Tartaric acid | Sharper acidity; good crystalline stability |
| Adipic acid | Mild acidity; lowest hygroscopicity; best for dry powders and tablets |
The choice depends on the product's pH, taste, moisture sensitivity, and formulation needs.
In H2 Tablets
Why Adipic Acid Is Part of the H2 Tablet Formula
Why it is used
Mild acidity with low hygroscopicity keeps dry powders and effervescent tablets free-flowing and stable.
In H2 Molecular Hydrogen Tablets, multiple acids work together to create the rapid effervescent chemistry that releases molecular hydrogen when the tablet contacts water.
Adipic acid is a formulation ingredient in H2 Molecular Hydrogen Tablets, not an active ingredient. The active benefit comes from molecular hydrogen and elemental magnesium.
Common Acidulant
Citric Acid
- Stronger, sharper acidity
- Highly hygroscopic; readily absorbs moisture
- More likely to cause clumping in dry formulations
Elemental Magnesium
The H₂ Source
80 mg of pure elemental magnesium (Mg) is the ingredient that generates molecular hydrogen when it reacts with water: Mg + 2H₂O → Mg(OH)₂ + H₂. Without the acids, this reaction takes hours, not practical for a supplement tablet.
Malic + Tartaric Acid
Primary Reaction Accelerators
Malic acid and L-tartaric acid are the primary reactive acids that lower pH and accelerate the magnesium-water reaction. They drive the main effervescent chemistry that dissolves the tablet rapidly and releases H₂ gas.
Adipic Acid
pH Buffer + Powder Stability
Adipic acid contributes mild additional acidity to the effervescent system while bringing its low hygroscopicity property, helping the tablet maintain good powder flow during manufacturing and resist moisture-related stability issues on the shelf.
Result
Hydrogen-Rich Water in Minutes
The combination of elemental magnesium, three food-grade acids, and dextrose creates a balanced effervescent tablet that dissolves rapidly to produce hydrogen-rich water with up to 12 PPM dissolved H₂, a selective antioxidant studied in multiple human trials.
Wellness Extract Products
H2 Tablets
Elemental Mg + Molecular H₂
H2 Tablets – Molecular Hydrogen Tablets by Wellness Extract
Enhance muscle recovery, boost hydration, and reduce oxidative stress with scientifically-backed molecular hydrogen—trusted by athletes to improve stamina, energy, and accelerate post-workout recovery.
80 mg Elemental MgUp to 12 PPM H₂Non-GMOThird-Party Tested
- Free shipping
- 30-day money-back guarantee
- Subscribe & save 20%
- COA available
- Free shipping
- 30-day money-back guarantee
- Subscribe & save 20%
- COA available
Evidence & References
Regulatory and Formulation Evidence for Adipic Acid
Adipic acid's evidence base is regulatory and formulation-based. No direct health benefits from adipic acid intake are claimed; its role is as a functional excipient.
01
FDA and International Regulatory Approval as a Food-Grade Acidulant
Adipic acid is recognized in 21 CFR 184.1009 as a GRAS food substance for use as a pH control agent, flavor enhancer/adjuvant, and leavening agent.
[1]
02
Adipic Acid Used in Hydrogen-Generating Effervescent Tablet Formulation
Published formulation research on hydrogen-generating effervescent tablets selected adipic acid based on regulatory acceptability and functional properties. Formulation evidence, not a health claim.
[2]Frequently Asked Questions
Answers About Adipic Acid in Wellness Extract Products
Adipic acid is a food-grade acidulant (E355) included as a formulation ingredient. It contributes mild acidity to the tablet's effervescent acid-base system, which accelerates the elemental magnesium-water reaction that generates molecular hydrogen when the tablet is dropped in water. It also helps maintain powder flow during manufacturing, thanks to its low hygroscopicity.
Adipic acid is the same molecule whether used industrially or in food applications. Most commercial adipic acid is produced for nylon manufacturing, but food-grade adipic acid is purified to meet food additive specifications (FDA 21 CFR 184.1009). Food-grade and supplement-grade adipic acid are produced and tested to confirm they meet these specifications.
Adipic acid is FDA GRAS (21 CFR 184.1009) and EU E355 approved for food use. It has an established safety record in food applications at relevant intake levels. The amounts used in supplement tablets are well within established food-additive parameters.
All three are organic acids used in food and supplement formulations. Adipic acid has lower acidity and notably lower hygroscopicity than citric acid, making it better suited for dry powder and tablet formulations that need to resist moisture. Malic acid has a smoother, prolonged tartness and is a natural Krebs cycle intermediate. Citric acid is strongest in acidity and most widely used but more likely to cause moisture-related stability issues in dry formulations.
Source Transparency
References
All footnoted claims link to peer-reviewed sources. Click any citation or this header to expand.
[1]
FDA 21 CFR 184.1009 — Adipic acid as a food substance — View source
[2]
Rösch et al., Pharmaceuticals, 2021 (PMID 34959728) — Hydrogen-generating effervescent tablet formulation — View on PubMed
Disclaimer
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. The information on this page is provided for educational purposes only and is not a substitute for professional medical advice. Always consult your physician or a qualified healthcare provider before starting any new supplement.
Stay in the Know
Join 25,000+ who get health tips, wellness hacks & anti-aging secrets delivered fresh each week.
- Choosing a selection results in a full page refresh.