Men vs. Women Peptide Dosing

Happy Wednesday!

Today, I will address a question I get pretty regularly from readers.

Totally fair question, because we’ve all been trained to think dosing = body size.

And for some things, that’s true.

But peptides play by a different set of rules than most people realize.

Most peptides aren’t “replacement” therapies the way testosterone, estrogen, progesterone, or thyroid hormone are.

Hormones are more like the gas in your fuel tank, whereas peptides are more like tune-ups for every other area of your car.

They bind to receptors, activate a signal, and trigger downstream cascades. Once you understand that, the unisex dosing makes a lot more sense.

So today, I’ll break down the real reason protocols often look identical across men and women, and then I’ll give you the exceptions so you don’t walk away thinking it’s always one-size-fits-all.

Receptors

A GLP-1 receptor doesn’t have a male version and a female version.

A ghrelin receptor doesn’t change because someone has higher estrogen.

The “lock and key” is the lock and key.

That’s why drugs like retatrutide are dosed the same way in men and women in the real world, even though outcomes can differ slightly (women often lose a bit more weight on average).

That difference isn’t usually fixed by changing the dose. It’s more about differences in physiology, appetite signaling, and how body composition shifts over time.

Same story with growth-hormone secretagogues.

When you activate that pathway, you’re telling the pituitary to do what it already knows how to do. Men and women both have that machinery.

Thresholds

This is where people get tripped up. With a lot of peptides, you reach an effective threshold where receptors are meaningfully activated, and the cascade is turned on.

After that, you get diminishing returns fast. More peptide doesn’t always mean more benefit.

Sometimes it just means more side effects, more water retention, more appetite changes, more cost, more noise.

That’s why “standard” protocols tend to cluster around similar mcg or mg ranges.

They’re trying to hit a practical sweet spot.

Strong enough to create a biological shift, conservative enough to avoid running the pathway too hard.

You can see this logic in clinical research too.

In the MK-677 trial in older adults, a single daily dose was used, growth hormone/IGF-1 levels rose, and fat-free mass improved over time, without splitting the protocol into “men’s dosing” and “women’s dosing.”

Pharmacokinetics

Many people assume that women and men metabolize substances differently.

Sometimes that’s true with specific oral drugs, especially when liver enzyme differences matter.

But most popular peptides are injected (or nasal), and they’re cleared by pathways that don’t reliably split by sex in a way that forces dosing differences.

Instead, what matters more is stuff like:

Peptide dosing has general “parameters” for both men and women, and then you adjust based on response.

That’s why you’ll see slow titrations and conservative ramps in the real world, especially with GLP-1s and anything that touches GH/IGF-1.

And again, the clinical data supports the idea that outcomes can differ by sex while the dosing protocol stays the same.

Use Cases

Injury repair peptides like BPC-157 are a perfect example.

The proposed mechanism is broadly pro-healing via growth factors, angiogenesis signaling, inflammation modulation, and tissue remodeling.

And the best human data we have is still limited, but a systematic review covering the broader evidence base notes a small human knee pain series alongside many animal models, with no indication that “female tissue needs a different dose.”

Immune peptides are the same concept.

Thymosin alpha-1 is used clinically as an immunomodulator, interacting with immune pathways (including TLR signaling) that exist in every human. Again, protocols don’t split into “men vs women,” because the goal is to shift immune behavior, not set sex-specific hormone levels.

Cognition peptides like Semax and Selank? Same story.

Semax is linked in research to changes in neurotrophic signaling like BDNF/TrkB, and Selank has published work on immune/cytokine modulation in anxious patients. Those systems don’t require gender dosing by default.

Even LL-37 research shows shared mechanisms like angiogenesis signaling tied to innate immunity and wound biology.

Final Thoughts

Peptide dosing is usually the same for men and women because:

Now the exceptions, because there are always exceptions.

If a peptide or compound causes side effects that are consistently more severe in one group, dose titration is warranted.

GLP-1 nausea sensitivity is a common example. Some people need a slower ramp.

If someone is very small, very large, has reduced kidney function, is on other meds that interact, is pregnant, breastfeeding, or has a complex medical history, you don’t “auto-pilot” dosing.

But as a general rule? For the major therapeutic peptides, dosing is primarily driven by receptor biology and thresholds. That’s why most protocols look the same.

As always, thank you for being a loyal reader and supporter of my work.

Best,

Hunter Williams

Further Reading