Huberman says brief sermorelin use spiked his PSA and suppressed REM sleep
"I've tried Smurellin very briefly. Dramatically increased my slowwave deep sleep. Nuked my REM sleep. This is a common theme. Spiked my prostate specific antigen. I've never had any problems with PSA. I came off it. PSA went back to normal."
About this episode
Tim Ferriss asks neuroscientist Dr Andrew Huberman for a practical framing of “peptides” amid rising public interest. Huberman defines peptides as short amino-acid chains naturally produced in the body and argues some become medicines when synthesised and delivered at very high doses. He contrasts older GLP drugs used for diabetes with newer agents that raise signalling “thousandfold”, which he says can drive robust weight loss but may also contribute to muscle loss, nausea, and (in some reports) reduced cravings for alcohol.
Huberman discusses Lilly’s retatrutide, describing it as a multi-pathway weight-loss drug (GLP, GIP and glucagon) that he says appears particularly effective and may spare some muscle; he also cautions that “grey market” peptides sold online as “research only” can be contaminated or mislabelled, and claims people are already self-administering unreleased compounds.
He then turns to growth-hormone secretagogues (including sermorelin and related variants), describing typical effects as modest and, in his view, often not worth the cost or risk compared with prescribed pharmaceutical growth hormone. Huberman shares a personal account of trying sermorelin briefly and experiencing altered sleep architecture and a transient PSA increase.
Finally, Huberman covers BPC-157, saying the animal literature is striking but that there are no published human trials. He argues it should not be used routinely and, if considered at all, should be reserved for injury contexts with attention to sourcing and clinical oversight.
Key takeaways
- Huberman defines peptides as endogenous amino-acid chains that can become medicines at high synthetic doses.
- He distinguishes newer GLP-based weight-loss drugs from earlier GLP treatments for diabetes, saying newer agents can drive large weight loss but may also contribute to muscle loss and nausea.
- He describes Lilly’s retatrutide as targeting GLP, GIP and glucagon pathways and suggests resistance training to mitigate muscle loss.
- Huberman warns that “research only” grey-market peptides can be contaminated or mislabelled, and claims unreleased compounds are already being self-injected.
- He describes growth-hormone secretagogues as often producing limited real-world changes in body composition compared with prescribed growth hormone.
- Huberman recounts trying sermorelin briefly and reports increased slow-wave sleep, reduced REM sleep, and a temporary PSA spike.
- He says BPC-157 has impressive animal data but no published human trials, and argues against ongoing routine use.