The Bacteriostatic Water Bundle: Why FDA Named BAC Water in Peptide Warning Letters (2026)

Seven 2026 FDA peptide letters name a water product on a seller's website or product list (REG-005, REG-017, OPS-102, OPS-107, OPS-108, OPS-109, OPS-110). Two, dated August 24, 2026, say "The sale of these products together demonstrates" an intent for it "to be used in combination for injection" (REG-013, REG-024, OPS-004, OPS-006). Source: FDA.

Updated October 28, 2026.

What is the short answer in one table?

FDA's NuScience letter says the sale of these products together "demonstrates that you intend" its "Bacteriostatic water for Peptides (BAC Water)" "to be used in combination for injection", and its Peptide Partners letter says the same of a product it calls "Reconstitution Solution (BAC)" (REG-013, REG-024). 21 CFR 201.128 says intent may be shown by "the circumstances surrounding the distribution of the article" (REG-003). In plainer words, both letters treat the sale of the products together as a sign of what the seller intends for the water product (REG-013, REG-024). Check each row of the table below against the source it cites before you rely on it (REG-003, REG-013).

What did FDA say about the water product in the NuScience letter?

The NuScience Peptides letter lists its water product among the products it calls unapproved new drugs (REG-005). The letter lists "Bacteriostatic water for Peptides (BAC Water)" as an unapproved new drug under section 505(a), together with GLP-2 Tirz Peptide, GLP-1 Sema Research Peptide, GLP-3 RT (Retatrutide) Research Peptide, Survodutide, Mazdutide, PT-141 Peptide (Bremelanotide), Tesamorelin Research Peptide and Tesamorelin Ipamorelin Blend (REG-005). In plainer words, the letter names the water product in the same list as the peptide products (REG-005). Compare your own product listings with the products FDA named in this letter (REG-005).

FDA's NuScience letter says selling the water product together with the other products shows an intent for it "to be used in combination for injection" (REG-013). FDA's NuScience letter says: "The sale of these products together demonstrates that you intend for your "Bacteriostatic water for Peptides (BAC Water)" to be used in combination for injection." (REG-013). peptideecommerce.com's own tool data dates the letter August 24, 2026 (OPS-004). In plainer words, FDA says selling the products together shows an intent for the water product to be used "in combination for injection" (REG-013). Review how your own listings present products together (REG-013).

What did FDA say about the water product in the Peptide Partners letter?

The Peptide Partners letter lists a product it calls "Reconstitution Solution (BAC)" among the products it calls unapproved new drugs under section 505(a) (REG-017). It says: "The sale of these products together demonstrates that you intend for your "Reconstitution Solution (BAC)" to be used in combination for injection." (REG-024). peptideecommerce.com's tool data records the letter as dated August 24, 2026 (OPS-006). Unlike the NuScience sentence (REG-013), this sentence names "Reconstitution Solution (BAC)" (REG-024). Compare how your own pages name any water or reconstitution product (REG-017, REG-024).

Which other 2026 letters name water?

Five other FDA letters have evidence quotes in peptideecommerce.com's tool data that name a water product, in wordings such as "Bac water" and "BAC Water" (OPS-102, OPS-107, OPS-108, OPS-109, OPS-110). The Gram Peptides record points to FDA's Gram Peptides letter (OPS-107). The captured sources do not give the full text of these letters. Read each full letter at FDA's site before you draw a conclusion about any one seller (OPS-107).

The site's records of FDA's 2026 letters to Gram Peptides, Pink Pony Peptides, Mile High Compounds and Prime Sciences each quote FDA naming a water product among what "your website offers" (OPS-107, OPS-108, OPS-109, OPS-110). The Pink Pony Peptides record names "Bacteriostatic Water", and the Mile High Compounds record names "BAC Water" (OPS-108, OPS-109). The site's record of FDA's Peak Performance Peptides letter also names "Bac water" (OPS-102). In plainer words, each of these five letters, as the site records it, names a water product (OPS-102, OPS-107, OPS-108, OPS-109, OPS-110). Read the full letters before you draw a conclusion about the water product in any one of them.

How did the letters spell the name of the water?

The letters quote the water product under different names (REG-005, REG-017, OPS-102). The NuScience letter quotes "Bacteriostatic water for Peptides (BAC Water)" (REG-005), and the Peptide Partners letter quotes "Reconstitution Solution (BAC)" (REG-017). The tool data records five further spellings: "Bac water", "Bacteriostatic Water for Injection", "Bacteriostatic Water", "BAC Water" and "BAC water" (OPS-102, OPS-107, OPS-108, OPS-109, OPS-110). In plainer words, the letters and the tool data do not use one name for the water product (REG-005, REG-017, OPS-102). Search your own pages for each of the names in the table (OPS-102, OPS-107).

How each of the seven letters names the water product

What does "circumstances surrounding the distribution" mean in the regulation?

The regulation lists the circumstances surrounding distribution as a way intent may be shown (REG-003). 21 CFR 201.128 says intent may be shown by such persons' expressions, the design or composition of the article, or by the circumstances surrounding the distribution of the article (REG-003). It gives labeling claims, advertising matter, and oral or written statements as examples of how objective intent may be shown (REG-002). The captured text does not define "circumstances surrounding the distribution" any further. Review how your own products are distributed and offered, using the regulation's list (REG-003).

21 CFR 201.128 says objective intent may be shown, for example, by circumstances in which the article is, "with the knowledge of such persons or their representatives, offered or used for a purpose for which it is neither labeled nor advertised" (REG-173). The same sentence adds a proviso: "a firm would not be regarded as intending an unapproved new use for an approved drug based solely on that firm's knowledge that such drug was being prescribed or used by health care providers for such use" (REG-173). In plainer words, the example concerns an article offered or used, with those persons' knowledge, for a purpose its labeling and advertising do not state (REG-173). The captured sources do not say that this example applies to selling products together. Compare your product labeling and advertising with how your products are actually offered (REG-173).

21 CFR 201.128: three ways objective intent may be shown

Which phrase of the regulation did FDA's bundling sentence use?

FDA's NuScience and Peptide Partners bundling sentences do not name a phrase of 21 CFR 201.128 (REG-013, REG-024). The NuScience letter says: "The sale of these products together demonstrates that you intend for your "Bacteriostatic water for Peptides (BAC Water)" to be used in combination for injection." (REG-013). The Peptide Partners letter says the same of its "Reconstitution Solution (BAC)" (REG-024). The NuScience letter introduces its examples as ones "that provide evidence of the intended use (as defined in 21 CFR 201.128)" (REG-006). The captured sources do not say that FDA relied on the "circumstances surrounding the distribution" phrase for the bundling sentence. Read the bundling sentence and the NuScience sentence that cites 21 CFR 201.128 before you link them (REG-013, REG-006).

What about "design or composition of the article"?

The regulation lists design or composition as a way intent may be shown (REG-003). The captured sources hold no FDA sentence that applies that phrase to the water product, reconstitution solution, a kit or a syringe. Compare the design and composition of your own products with the regulation's wording (REG-003).

Do kits, syringes or bundles appear anywhere else in the ledger?

The ledger holds no entry on kits, syringes or bundles. A search of the ledger for "kit", "syringe" and "bundle" returned no match. The sentence about selling products together comes from FDA's NuScience and Peptide Partners letters (REG-013, REG-024). So this guide reports nothing about kits or syringes. Read FDA's own letters for any statement about kits or syringes.

peptideecommerce.com's own COA tool data also mentions water, outside the letters (OPS-026, OPS-095). Its COA glossary defines "Water content" as "The measured water in the material." (OPS-026) Its COA checklist asks whether water lines are present or marked not tested (OPS-095). In plainer words, these entries concern lab reports and not FDA's letters (OPS-026, OPS-095). Use them when reading a COA and not when reading the letters (OPS-026, OPS-095).

Does a research use label change what FDA wrote about the products?

FDA's NuScience letter quotes the seller's label wording "for laboratory, research, and analytical use" and "not intended for human or veterinary use," in a sentence that begins "Despite statements on your product labeling" (REG-015). In plainer words, FDA quoted the seller's label wording back in that sentence (REG-015). The Peptide Partners letter quotes "for research use only" and "not for human or veterinary use," in a sentence that begins "Despite statements on your product labeling" (REG-026). The captured sources do not say whether the water products in those letters carried the same label wording as the other products. Compare the label wording on your water or reconstitution products with the wording on your other products (REG-015, REG-026).

What other website evidence sat beside the water in those letters?

FDA's NuScience and Peptide Partners letters each state that "evidence obtained from your website establishes that your products are intended to be drugs for human use" (REG-014, REG-025). The NuScience letter describes its examples as coming from "your product labeling, including on your website" (REG-006). In plainer words, FDA says evidence from the seller's website establishes what the products are intended to be (REG-014, REG-025). The captured sources do not say whether FDA would have named the water without the other products on the same site. Review the website text around your water product as well as the listing itself (REG-014, REG-025).

What did the letters say happens next?

FDA's NuScience and Peptide Partners letters each state that "The introduction or delivery for introduction into interstate commerce of these unapproved new drug products violates sections 301(d) and 505(a) of the FD&C Act, 21 U.S.C. 331(d) and 355(a)." (REG-186, REG-198). They also set a response window of "within fifteen (15) business days of receipt of this letter" (REG-068, REG-071). In plainer words, each letter pairs a violation finding with a fifteen business day response window (REG-186, REG-198, REG-068, REG-071). Note the response period in any FDA letter your firm receives (REG-068, REG-071).

FDA's NuScience letter warns: "Failure to adequately address violations may result in regulatory or legal action without further notice including, without limitation, seizure and injunction." (REG-016). The Peptide Partners letter holds the same sentence (REG-199). Both the NuScience letter (REG-179) and the Peptide Partners letter (REG-191) say: "If you have information that you believe demonstrates that your products are not in violation of the FD&C Act and FDA regulations, include that information for our consideration." In plainer words, the warning says failure to address the violations adequately may bring regulatory or legal action, and the invitation asks for information the recipient believes shows its products are not in violation (REG-016, REG-179). Read the warning and the invitation in the letters before you reply to any FDA letter (REG-016, REG-179).

What can this guide not tell you?

The captured sources hold the full bundling sentence in the NuScience and Peptide Partners letters and a recorded quote naming water for the other sellers (REG-013, REG-024, OPS-102). They hold no kit entry, no syringe entry, and no FDA text that explains why water was named beyond the bundling sentence. Read the letters themselves for anything this guide does not cover.

An FDA warning letter supports only the statement that FDA cited a seller for something. It does not support a statement about any compound or product being illegal. Talk to a licensed attorney for your situation.

FAQ

Which sellers did FDA tell that selling water together with other products shows intent?

NuScience Peptides and Peptide Partners, in the sentences quoted above (REG-013, REG-024).

Was the water product listed as an unapproved new drug?

The NuScience letter lists "Bacteriostatic water for Peptides (BAC Water)" among products that "are unapproved new drugs under section 505(a)" (REG-005). The Peptide Partners letter does the same for "Reconstitution Solution (BAC)" (REG-017). Source: FDA NuScience letter.

Does the ledger say kits or syringes were cited?

No. The sources captured for this guide do not say.

What do the words "the sale of these products together" refer to?

The sentence refers to the products listed in the same letter (REG-005, REG-013). The sources captured for this guide do not describe how the products were packaged or priced.

Which regulation do the letters cite for intended use?

The NuScience letter cites intended use "as defined in 21 CFR 201.128" (REG-006).

Does the regulation list the circumstances of distribution as evidence?

Yes. It says intent may be shown by the circumstances surrounding the distribution of the article (REG-003).

How many days did the letters give?

Fifteen business days from receipt (REG-068, REG-071).

Is this legal advice?

No. Talk to a licensed attorney for your situation.

Sources