Compare prices and buy Acetic Acid from 16 research peptide vendors - also called suppliers or sources. Updated daily.
A two-carbon carboxylic acid, CH3COOH (C2H4O2, CAS 64-19-7), and not a peptide. Peptide vendors sell a dilute sterile solution of it, usually labeled 0.6%, as a solvent for lyophilized peptides. A peptide manufacturer's handling guide lists dilute acid such as acetic acid as an option for basic peptides that dissolve poorly in water. No FDA-approved application covers acetic acid as an injected active ingredient or as a standalone diluent. For research purposes only.
For research purposes only. Not medical advice.
Acetic acid is not a peptide. It is a two-carbon carboxylic acid, CH3COOH (formula C2H4O2, molecular weight 60.05, CAS 64-19-7), the acid in vinegar. PeptideScouter catalogues it under Reconstitution because peptide vendors sell a dilute sterile solution of it as a solvent, next to bacteriostatic water and sterile water.
It is a weak acid, with a pKa of 4.76 at 25 C in the Hazardous Substances Data Bank record that PubChem carries. Listings typically label the solution 0.6%, and none of the product pages read states whether that percentage is by weight or by volume. Either way it works out to about 0.1 molar, a strength the same record puts at pH 2.9. For comparison, the FDA-approved 0.25% Acetic Acid Irrigation USP is labeled at about pH 3, within a range of 2.8 to 3.4.
Bachem, a peptide manufacturer, ties a peptide's solubility mainly to its charged groups. Its handling guide counts the acidic and basic residues, including the two ends of the chain, and sorts peptides three ways:
The same guide notes that many charged peptides dissolve in neutral phosphate-buffered saline anyway at low concentrations. The rule shows which direction helps when water fails.
BPC-157 shows why the count matters. Its 15 residues include three acidic ones and a single lysine, which places it in the acidic group, and FDA's July 2026 compounding review describes it as soluble in water, citing a supplier's product page.
PeptideScouter found no manufacturer or regulator document naming acetic acid as the solvent for the last four.
Acetic acid reaches peptides a second way. Synthetic peptides leave purification paired with trifluoroacetate, which binds their basic groups, and a 2025 study in Pharmaceuticals recommends replacing it with a more physiological ion such as chloride or acetate. Drugs@FDA lists the active ingredients of several approved peptide drugs as acetate salts: sermorelin acetate (Geref, discontinued), tesamorelin acetate (Egrifta), leuprolide acetate (Lupron Depot) and octreotide acetate (Sandostatin LAR and generic octreotide injections). FDA's Category 2 compounding list names ipamorelin acetate under 503B.
The counterion adds mass. Cayman's GHRP-6 is a triacetate with a formula weight of 1,053, against about 873 for the peptide alone, so a weighed milligram of the salt holds less than a milligram of peptide.
As of October 20, 2026:
The dilute solution sold for peptide research is covered by none of those approvals, while Hospira's bacteriostatic water is marketed under NDA 018802.
A dilute solution of acetic acid, CH3COOH (CAS 64-19-7), in sterile water, sold by peptide vendors as a solvent. Acetic acid is a two-carbon carboxylic acid, not a peptide. Listings typically label the solution 0.6%, which is roughly 0.1 molar whether the percentage is by weight or by volume, and the Hazardous Substances Data Bank puts a 0.1 molar solution at pH 2.9. Vendor pages do not say which percentage basis they use.
Mainly basic ones. Bachem's peptide handling guide ties solubility to charge: peptides with more basic than acidic groups may dissolve in dilute acid such as acetic acid, acidic peptides in dilute base, and hydrophobic peptides in a small amount of organic solvent. IGF-1 LR3 is the documented case, since Repligen names 100 millimolar acetic acid, about the strength of a 0.6% solution, as its solvent. Cayman Chemical's data sheets describe GHK-Cu, GHRP-2 and GHRP-6 dissolving in water or neutral buffer, and FDA's compounding reviews describe BPC-157 and AOD-9604 as water-soluble.
No. As of October 20, 2026, Drugs@FDA lists acetic acid as the active ingredient only of bladder irrigations and ear drops, and no approved application covers it as an injected active ingredient or as a standalone diluent. FDA's Inactive Ingredient Database lists it as an excipient in approved injectables, often for pH adjustment, and 21 CFR 184.1005 affirms it as generally recognized as safe in food. Hospira's bacteriostatic water, by contrast, is marketed under NDA 018802.
Because of how they are made. Synthetic peptides leave purification paired with trifluoroacetate, which binds their basic groups, and a 2025 study in Pharmaceuticals recommends replacing it with a more physiological ion such as chloride or acetate. Several FDA-approved peptide drugs list acetate salts as their active ingredients, including tesamorelin acetate, leuprolide acetate and octreotide acetate. The acetate adds mass: Cayman Chemical's GHRP-6 triacetate has a formula weight of about 1,053 against about 873 for the peptide alone.
Because it is a solvent sold by volume. Acetic acid water comes as a liquid measured in millilitres, and the per-milligram figure used across the site is computed only for products sold by mass in vials. A per-milligram price for a dilute acid would not compare like with like, so these listings are compared on price per vial and vial volume instead, the same convention used for bacteriostatic water and sterile water.
Acetic Acid is sold by 16 research peptide vendors indexed on PeptideScouter, with 20 tracked listings compared per vendor in the table above. Pricing is normalized and refreshed daily.
14 of the 16 indexed vendors currently have Acetic Acid in stock. The comparison table marks out-of-stock listings, and stock state is refreshed daily.
Discount codes are issued per vendor rather than per peptide, so any code applies across that vendor's whole catalog. All 16 vendors listing Acetic Acid publish a PeptideScouter code, worth 10% to 20% off. These listings do not carry a comparable per-milligram price, so code availability is shown without a normalized effective price. Each vendor's code is shown beside its price in the table above.
16 research peptide vendors currently list Acetic Acid on PeptideScouter, with 14 in stock right now. We track 20 listings across size and kit variants.
Acetic Acid's CAS Registry Number is 64-19-7. It is also sold as Acetic Acid 0.6%, AA WATER, Acetic Acid (Reconstitution Solution).
