Compounding
How compounding rules and FDA's bulk-substance categories work.
Ever read a headline about a "compounded" drug and wondered what that means? Compounding is when a pharmacist or physician makes a customized medicine instead of dispensing a mass-produced, FDA-approved one. Many peptide headlines are really compounding headlines.
Two sections of federal law matter. Section 503A governs compounding done by pharmacies licensed in their state, by federal facilities and by licensed physicians. Section 503B covers outsourcing facilities that register with FDA. [V] For each, FDA keeps a "bulks list" of substances that may be used. Nominated substances not yet on the 503A list are sorted into Categories 1 to 3 under an interim policy, which describes FDA's enforcement stance and is not an approval. [V] FDA also states that compounded drugs are not FDA-approved. [V]
Evidence labels: [V] verified in a primary document, [S] secondary source. Reviewed October 25, 2026.
Posts in this topic
- Safety and quality
- Compounding
- Wellness
The glutathione injection recall: what FDA's October 1 notice says, and what it doesn't
FDA's Oct 1, 2026 notice on a compounded glutathione injection recall for possible endotoxin: what it says, what CDC and FDA add, what's unconfirmed.
- Compounding
- Advisory committee
- Wellness
GHK-Cu is in skincare and on FDA's compounding list. Here's what "except injectable" means
GHK-Cu, the copper peptide in skincare, is on FDA's Category 1 compounding list except for injectables, with an advisory meeting due by February 2027.
- Compounding
- FDA
- Safety and quality
What FDA's "Category 1" and "Category 2" actually mean (and what they don't)
What FDA's Category 1 and Category 2 labels for compounded bulk substances mean, and what they do not mean, using FDA's own documents.
- Wellness
- FDA
- Compounding
"It's a peptide": three very different things hiding behind one word
Approved peptide medicines, compounded drugs and wellness-market peptides side by side: what FDA reviewed, what a label tells you, and what it does not.
Common questions
Are compounded drugs FDA-approved?
No. FDA's Questions and Answers page says they are not. [V]
Is Category 1 an approval?
No. Category 1 is a limited enforcement stance: for a substance FDA is evaluating, it says it "does not intend to take action against a compounder" who meets its conditions. [V]
Key terms in plain English
- 503A
- The part of the Food, Drug, and Cosmetic Act for pharmacy and physician compounding. [V]
- 503B
- The part for outsourcing facilities that register with FDA. [V]
- Bulks list
- The list FDA keeps of bulk ingredients that compounders may use under that section. [V]
- Interim policy
- FDA's stopgap enforcement approach while it evaluates nominated substances. [V]
Primary sources behind this page
- FDA, Section 503A bulk drug substances (retrieved Oct. 25, 2026)
- FDA, Section 503B bulk drug substances (retrieved Oct. 25, 2026)
- FDA, Compounding and the FDA: Questions and Answers (retrieved Oct. 25, 2026)
- FDA, Compounding categories list (PDF) (posted May 14, 2026)