Peptide boom exposes evidence gaps as drug development and prescribing markets draw interest

Tirzepatide generated nearly $44 billion in sales in the first nine months of 2026, highlighting the commercial scale of an approved peptide medicine. Interest has spread to unapproved compounds, but their supporting evidence and market size differ sharply.

In its “The State of Longevity” report published on November 3, 2026, Andreessen Horowitz said Eli Lilly recorded those sales through its Mounjaro and Zepbound brands. That puts a single FDA-approved medicine well ahead of the compounded peptide market, which the report described as worth single-digit billions of dollars.

The report traced the broader peptide boom to the success of GLP-1 receptor agonists in diabetes, obesity and cardiovascular care. Greater familiarity with self-injection at home, alongside easing regulation, has helped extend consumer interest to other peptides.

Consumers are experimenting with unapproved compounds marketed for recovery, performance and appearance, including BPC-157 for tissue repair and melanotan II for tanning. Andreessen Horowitz said enthusiasm has run ahead of the evidence: many compounds lack strong human data establishing safety and efficacy, while unregulated suppliers raise questions about what their products actually contain.

The report said a recent policy from the Department of Health and Human Services eases enforcement against licensed pharmacies compounding six peptides under specified conditions. Those peptides remain unapproved by the FDA, and questions about their safety and efficacy remain unresolved.

In drug development, Andreessen Horowitz expects the pipeline of rigorously tested, FDA-regulated peptide medicines to expand. It also anticipates greater investor interest in drugs that combine established safety and efficacy standards with strong consumer demand. The report argued that such demand could help developers reach patients more efficiently, addressing a longstanding difficulty in matching treatments with clinical need. It suggested that this pattern could extend to sleep, bone health and cardiovascular health.

In healthcare delivery, the report outlined a possible repeat of the GLP-1 cycle if additional peptide medicines establish safety and efficacy and achieve broad adoption. Dedicated prescribing businesses could emerge, following the examples of Calibrate, Found and Weekend Health, before existing healthcare companies add peptide prescriptions. However, Andreessen Horowitz noted that although GLP-1 medicines helped care delivery companies grow, most of the resulting enterprise value accrued to pharmaceutical companies.

As more providers prescribe the same medicines, the report suggested, access alone could become a weaker competitive advantage. Peptide prescribing could become a service patients routinely expect, making it more significant for retaining existing patients than attracting new ones.