Clinician
How I reason about peptide protocols.
Every protocol surfaced in the chat is reviewed against the principles below. If a recommendation does not pass them, the guide does not make it — even when it would be easier to say yes.
Dr. Maya Levin, MD
Board-certified Internal Medicine · 11 yrs · San Francisco, CA
“I recommend the smallest, best-evidenced peptide that fits your goal — and stop when you're done. Most of you need one, not three.”
CA license A157892 · NPI 1467821093
Reasoning
Most people who ask me about peptides arrive with a stack — three, four, sometimes six compounds someone on a podcast described as synergistic. My job is usually to take things away. The body responds to one well-chosen signal more reliably than to a chorus of overlapping ones, and the side-effect surface scales faster than the benefit.
When I write a protocol I start from the goal, not the molecule. If the goal is sleep depth, I look at what is actually broken — sleep onset, fragmentation, recovery — and only then ask which peptide, if any, has human data for that specific failure mode. Often the answer is none, and the right intervention is behavioral or a known oral compound with twenty years of safety data.
When a peptide is the right tool, I prefer the shortest course that achieves the goal. A six- to twelve-week cycle, a clear stop criterion, and an honest reassessment beat indefinite use almost every time. We are still early in understanding long-horizon effects of chronic exogenous signaling, and humility belongs in the protocol.
I also believe in saying no, plainly. I will not recommend a peptide because someone wants to feel like they are optimizing. The placebo of doing something is expensive — financially, metabolically, and in the attention it pulls away from sleep, training, and food, which still dominate every outcome that matters.
Principles
- 01
One signal at a time
Stacks make attribution impossible. If three things change at once and you feel better, you have learned nothing about what worked. I sequence interventions so the signal is legible.
- 02
Stop when you are done
Peptides are tools, not subscriptions. Every protocol I write has an explicit stop criterion — a metric, a window, or a feel — and a plan for what comes off-cycle.
- 03
Evidence over enthusiasm
I weight human trials over animal models, mechanism over marketing, and replicated results over a single charismatic study. Where the evidence is thin, I say so out loud in the protocol.
- 04
Foundations first
If sleep, protein intake, resistance training, and sunlight are not in place, no peptide will outrun their absence. I will tell you to fix those first, even when it is not what you came in to hear.
What I will not recommend
- Indefinite, open-ended cycles without a clear stop criterion
- Stacks of three or more peptides on first protocol
- Injectable compounds for goals an oral or behavioral intervention covers
- Anything currently on the WADA prohibited list for athletes in testing pools
- Peptides during pregnancy, nursing, or for anyone under 18
Training
- University of California, San Francisco
- MD, School of Medicine
- Stanford Health Care
- Internal Medicine residency
- American Board of Internal Medicine
- Board-certified, recertified 2024
- Private practice, San Francisco
- Longevity and metabolic medicine, 2016 – present
Ready to map this to your own goal? The guide will translate these principles into a specific, time-bound protocol — or tell you that you do not need one.
Talk to the protocol guideCA license A157892 · NPI 1467821093
Educational only. Not medical advice. These statements have not been evaluated by the FDA. Talk to your own clinician before starting any new compound, especially if you are pregnant, nursing, under 18, or taking prescription medication.