FDA warns Gram Peptides over tirzepatide and retatrutide sales
The March 31 letter says selling tirzepatide, retatrutide and bacteriostatic water makes them unapproved drugs, leaving buyers without FDA-reviewed safety, purity or dosing.
The Food and Drug Administration has told Gram Peptides, a company based in Rancho Santa Fe, California, that it is selling tirzepatide, retatrutide and bacteriostatic water for injection as unapproved new drugs, and that labeling the products "Research Use Only" does not put the sales outside drug rules [1].
The warning letter is dated March 31, 2026 and comes from the FDA's Center for Drug Evaluation and Research [1]. Agency staff reviewed the website grampeptides.com from January through March 2026, according to the letter [1]. The site offered "Retatrutide" (which the company also calls "GLP-1-R peptide"), "Tirzepatide" (which it calls "GLP-2 peptide") and "Bacteriostatic Water for Injection" for sale in the United States [1]. FDA says all three are unapproved new drugs under section 505(a) of the Federal Food, Drug, and Cosmetic Act, and that no approved applications are in effect for them [1].
FDA says the site's own product descriptions show the peptides are intended for people, not laboratory work. For retatrutide, the letter quotes the site saying the product "[i]nfluences appetite suppression, insulin sensitivity, thermogenesis, and fat-oxidation models," has "[d]emonstrated significant potential for reducing body weight, improving glucose handling, and enhancing lipid metabolism," and acts through GLP-1 receptors, "improving glucose response, slowing gastric emptying, and reducing appetite" [1]. For tirzepatide, the letter quotes listed benefits including "Metabolic Regulation — Studied for its ability to lower glucose and support balanced insulin levels," "Weight Management — Associated with significant decreases in body weight in both animal and human studies," and "Improved Lipid Profiles" [1].
The bacteriostatic water drew separate attention. According to the letter, Gram Peptides sells it alongside peptide products that are drugs intended for injection and that require reconstitution, and selling them together "demonstrates that you intend for your 'Bacteriostatic Water for Injection' to be used in combination for injection" [1]. On that basis, FDA classified the water as a drug too [1].
FDA says injectable products are "especially concerning from a public health perspective" because they go directly into the body, sometimes into the bloodstream, bypassing some of the body's defenses against toxins and microorganisms that can cause serious and life-threatening conditions [1]. The letter does not describe any patient injuries, illnesses or product test results tied to this company, and it does not say how much product was sold or to whom.
Why it matters for patients
A warning letter is an enforcement step against a seller, not a finding about any one person's supply. Even so, the letter lays out what buyers of these specific products are and are not getting. FDA says none of the three products has an approved application, which means the agency has not reviewed them for safety, effectiveness, purity, sterility or correct dosing [1]. That review is what stands behind prescription versions of approved drugs.
The "Research Use Only" language on a label does not settle the question on its own. FDA says it looks at the surrounding marketing — what a seller claims a product does and what it ships with the product — to decide whether the items are intended for human use [1]. In this case, the letter points to human weight, blood sugar and appetite claims plus the sale of bacteriostatic water, which is used to dissolve powdered peptides before injection [1].
For anyone who has bought peptides sold this way, the practical consequence is that there is no FDA-verified dose, no assurance the vial contains what the label says, and no sterility guarantee behind an injectable. The letter also notes the general risk that injected products can introduce toxins or microorganisms directly into the body [1]. It does not say whether any batch from this company was tested or found contaminated.
What happens next
Gram Peptides has 15 working days from receipt of the letter to tell FDA in writing what steps it has taken to correct the violations, to explain how it will prevent them from recurring, or to argue that its products do not violate the law, according to the letter [1]. Responses go to FDA's Office of Unapproved Drugs and Labeling Compliance by email, with the identifier 721806 in the subject line [1].
FDA says failure to adequately address the matter may lead to regulatory or legal action, including seizure and injunction [1]. Whether the company has responded has not been disclosed, and the letter does not set a date for any further action.
Sources
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