NuScience Peptides LLC: FDA Warning Letter (August 24, 2026)

Summary

Company

NuScience Peptides LLC

Letter number

#733652

Issue date

August 24, 2026

Subject

Unapproved New Drugs/Misbranded

This letter is one of a run to online sellers of research-use peptides: FDA warning letters to peptide sellers, 2023 to 2026.

FDA’s letter of August 24, 2026 to Peak Performance Peptides also cites its recipient for selling products FDA calls unapproved new drugs.

Word for word, from the letter of August 24, 2026

This warning letter advises you of significant violations observed during a U.S. Food and Drug Administration (FDA) review of your website. Promptly address the violations described herein without delay, including ensuring that appropriate resources are allocated to fully address the violations and prevent their recurrence. This is not intended to be an all-inclusive list of the violations that may exist in connection with your products or operations. It is your responsibility to ensure that your firm complies with all requirements of federal law, including FDA regulations. Failure to adequately address violations may result in regulatory or legal action without further notice including, without limitation, seizure and injunction.

These products are especially concerning from a public health perspective because injectable drug products can pose risks of serious harm to users. Injectable products are delivered directly into the body, sometimes directly into the bloodstream, and therefore, bypass some of the body’s key defenses against toxins and microorganisms that can lead to serious and life-threatening conditions.

Violations were identified and documented during a review of your website nusciencepeptides.com in July 2026. Based on our review, “GLP-2 Tirz Peptide,” “GLP-1 Sema Research Peptide,” “GLP-3 RT (Retatrutide) Research Peptide,” “Survodutide,” “Mazdutide,” “PT-141 Peptide (Bremelanotide),” “Tesamorelin Research Peptide,” “Tesamorelin Ipamorelin Blend,” and “Bacteriostatic water for Peptides (BAC Water)” are unapproved new drugs under section 505(a) of the Federal Food, Drug, and Cosmetic Act (FD&C Act), 21 U.S.C. 355(a). As explained further below, introducing or delivering these products for introduction into interstate commerce violates sections 301(d) and 505(a) of the FD&C Act, 21 U.S.C. 331(d) and 355(a).

This review was conducted as part of FDA’s public health responsibility to protect the public from unsafe, ineffective, and poor-quality drugs.

The following are violations identified during our review. As a reminder, this is not an all-inclusive list of violations that may exist in connection with your products or operations.

Based on a review of your website, “GLP-2 Tirz Peptide,” “GLP-1 Sema Research Peptide,” “GLP-3 RT (Retatrutide) Research Peptide,” “Survodutide,” “Mazdutide,” “PT-141 Peptide (Bremelanotide),” “Tesamorelin Research Peptide,” “Tesamorelin Ipamorelin Blend,” and “Bacteriostatic water for Peptides (BAC Water)” are drugs under section 201(g)(1) of the FD&C Act, 21 U.S.C. 321(g)(1), because they are intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease, and/or intended to affect the structure or any function of the body.1 Examples from your product labeling, including on your website, that provide evidence of the intended use (as defined in 21 CFR 201.128) of these products as drugs include, but may not be limited to, the following:

GLP-1 Sema Research PeptideOn the webpage https://pubchem.ncbi.nlm.nih.gov/compound/56843331#datasheet=LCSS (hyperlinked from https://nusciencepeptides.com/product/glp-1-sm/):

GLP-3 RT (Retatrutide) Research PeptideOn the webpage https://nusciencepeptides.com/product/glp-3-rt/:

Despite statements on your product labeling marketing your products “for laboratory, research, and analytical use” and “not intended for human or veterinary use,” evidence obtained from your website establishes that your products are intended to be drugs for human use. In addition to the cited drug claims, you market bacteriostatic water alongside a “peptide calculator,” a resource that provides the means to prepare an injectable drug for human administration.

Quoted word for word from the U.S. Food and Drug Administration. We assert nothing beyond what the agency published, and the full letter is at https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/nuscience-peptides-llc-733652-08242026

What FDA warning letters mean

Other warning letters in our database

• Pink Pony Peptides — March 31, 2026
• Peaks — February 20, 2026
• Canada Med Stop — September 9, 2025
• HealBerry — September 9, 2025
• Vitals RX — September 9, 2025