Peptides are everywhere right now. They are being marketed for fat loss, injury recovery, anti-ageing, gut health, energy, and almost every other wellness promise you can imagine. But behind the hype, there is a much more important question: what do we actually know?
In this episode, I sit down with Dr Leigh Baxt to unpack the science of peptides, how medicines are really developed, and why the current peptide boom should make us pause. We explore the gap between compelling marketing and real evidence, why anecdotes are not enough, and what concerns scientists who work close to the drug development pipeline.
What We Cover
- What peptides actually are, and why they are not a new invention
- The difference between FDA-approved peptide drugs and peptides sold online for “research use only”
- Why the current peptide craze concerns many scientists
- How the drug development process works from idea to approved medicine
- Why more than 99 percent of drug ideas fail before reaching patients
- The difference between promising animal or cell data and evidence in humans
- Why “natural” does not automatically mean safe
- How anecdotal success stories can mislead when safety and efficacy are still unknown
- Why patentability is not the main reason these peptides remain unapproved
- How to think more critically about bold peptide claims online
This conversation is a reminder that scientific uncertainty matters. When a compound has not gone through proper testing, the biggest issue is not whether the marketing sounds convincing, but whether the benefits, risks, dose, and mechanisms are actually understood.
To learn more from Dr Leigh Baxt, follow her on Instagram at @sciencemomscicomm. I also recommend exploring Unbiased Science, where science communication is made far more accessible for the public. You can follow the project on Instagram, Threads, Facebook, LinkedIn, X, subscribe on Substack, and watch on YouTube.
- Intro (00:00)
- Stanford Expert Breaks Down the Peptide Hype (00:53)
- The Skill Set Behind Real Drug Development (05:09)
- FDA Approved vs Research Only Peptides Explained (08:03)
- Why Most Drug Candidates Never Become Medicine (11:06)
- Peptide Reclassification What Changes and What Doesn’t (15:59)
- The Biological Risks Nobody Mentions About Peptides (20:36)
- Why Natural Peptides Are Not Necessarily Safe (23:00)
- What Safety Tests Drugs Must Pass First (28:51)
- Accepting Unknown Risk What That Actually Means (33:31)
- How to Find Credible Health Experts Online (36:13)
- Why Drug Development Always Requires A Team (39:19)
Subscribe and stay connected:
Subscribe to The Proof on YouTube, Apple Podcasts or Spotify to ensure you never miss an episode. And don’t forget to follow me on Instagram and X for more insights and updates.
This episode is brought to you by:
38TERA
Consider 38TERA’s DMN prebiotic supplement a daily multivitamin for your gut. Formulated by yours truly and gastroenterologist Dr Will Bulsiewicz. Use code THEPROOF for a discount at checkout.
38Tera ships to the United States, Australia, and New Zealand.
Function Health
Take charge of your health with advanced blood testing and personalised insights. Function Health offers a practical way to track key health markers such as cholesterol, blood sugar, and more. Learn more and join at functionhealth.com/simonhill for a $25 credit toward your membership. Only available to those living in the United States.
Function Health ships to 48 U.S. states, excluding Rhode Island, Hawai‘i, and Puerto Rico.
Cozy Earth
Cozy Earth’s sheets are designed to keep you cool by wicking heat and moisture away from your body, helping you sleep deeper and wake less. Get up to 20% off at cozyearth.com with code THEPROOF.
Cozy Earth ships worldwide.
Eight Sleep
Upgrade your sleep with the Pod 5 Ultra by Eight Sleep. Clinically validated to deliver up to 1 extra hour of quality sleep per night through temperature control and biometric tracking. Use code THEPROOF for $350 off at eightsleep.com/theproof. Try it risk-free for 30 days, with worldwide shipping.
Eight Sleep ships to the U.S. (excluding Alaska, Hawaii, and territories), Canada, Mexico, most of the EU, the U.K., Australia, the UAE, Saudi Arabia, and Switzerland.
ProLon
Ready for your own reset? For a limited time, ProLon is offering The Proof listeners 15% off sitewide plus a $40 bonus gift when you subscribe to their 5-Day Program. Visit ProLonLife.com to claim your discount and bonus gift.
ProLon ships within the United States.
WHOOP
Whoop, the most advanced fitness and health wearable available. Your personalised fitness and health coach to recover faster, sleep better, and train smarter. Claim your first month free on join.whoop.com/simon.
Whoop ships to 56+ international markets, including the US, Canada, most of Europe, Australia, New Zealand, UAE, Singapore, and parts of Asia.
More about Leigh Baxt
Leigh Baxt, PhD, is a translational and drug development scientist specializing in the interface between basic biology and therapeutic development. Her work focuses on advancing early-stage ideas from basic science through in vivo validation, generating rigorous, decision-enabling data to determine which therapeutic concepts are robust enough to progress.
She has contributed to more than 30 therapeutic programs across oncology, metabolic disease, infectious disease, and regenerative medicine, with experience spanning small molecules, biologics, and PROTACs, along with earlier-stage work in drug conjugate modalities including antibody–drug conjugates (ADCs), small molecule drug conjugates (SMDCs), and peptide drug conjugates (PDCs). Leigh teaches translational science to a range of audiences, mentors junior scientists, and shares science communication content on Instagram as a way to extend her teaching beyond the lab.
Leigh earned her PhD in Microbiology and Immunology from Stanford University School of Medicine and completed her postdoctoral training at Harvard Medical School. She brings an evidence-based, translational lens to discussions of emerging therapeutics, grounded in how drugs are actually developed, tested, and translated into clinical use.
The views expressed are her own and she is not representing her employer.
