Brad | DocBiohacker

Physician. Separating evidence from hype in longevity, metabolic health, and wellness — no selling, just the actual research. Not intended as medical advice.

[Brad | DocBiohacker @DocBiohacker]

Can you use GHK-Cu and tretinoin together?

Yes, there's no known pharmacologic interaction between them.

But it's best to separate them in time rather than mix them in the same application: GHK-Cu's stability depends on a specific serum environment, and tretinoin's cream or gel base can theoretically shift that environment enough to accelerate peptide breakdown if applied at the same time.

[Brad | DocBiohacker @DocBiohacker]

Good point! Fructose does raise triglycerides, but it’s thought to do so in a dose dependent way at intakes above what a typical whole fruit serving would provide. The fiber and bulk make it harder to overshoot the triglyceride-raising dose compared to juice. But point well taken - whole fruit isn't magically exempt.

[Brad | DocBiohacker @DocBiohacker]

Two things worth separating here: (1) semaglutide extended lifespan vs. untreated mice by 12%. (2) In a separate analysis, semaglutide outperformed calorie-restricted mice on exploratory drive, spatial memory, and glucose control showing functional benefits beyond what calorie restriction alone produces.

Caveat: survival itself was never directly compared between the semaglutide and calorie-restriction groups, so we can't say which extends lifespan more.

[Brad | DocBiohacker @DocBiohacker]

@creatorschmidt And the relationship is bidirectional, stress and mood also reshape the microbiome!

[Brad | DocBiohacker @DocBiohacker]

@davidasinclair Worth adding: it's not just that selection tapers off, antagonistic pleiotropy suggests some genes are actively selected for early-life reproductive fitness even when they cause harm later.

[Brad | DocBiohacker @DocBiohacker]

100% agree! Penetration is driven by the base (cream, lotion, gel, ointment, serum, emulsion, or solution) which is why 2 products at the same % can differ in what reaches viable skin

Question, is there anything on a label you can actually use to judge delivery e.g., pH, emulsion type or is it hard to say without permeation data?

[Brad | DocBiohacker @DocBiohacker]

Copper peptides aren't a new trend. GHK-Cu has been studied in skin biology since the 70s.

GHK occurs naturally in the body but declines with age, tracking the drop in regenerative capacity.

In skin, GHK-Cu stimulates collagen synthesis and matrix remodeling, supports wound healing, and acts as an antioxidant.

Unlike retinoids, it shows little irritation making it a reasonable option for people who can't tolerate a retinoid routine.

The mechanism is real, but the evidence is mostly in vitro and small cosmetic trials not the depth behind retinoids or sunscreen, and it isn't approved as a drug for any indication.

Promising mechanism, still an emerging evidence base.

[Brad | DocBiohacker @DocBiohacker]

@LiveAncestral Worth noting this lines up with the TRE (time-restricted eating) literature, where several trials show modest metabolic benefits from eating earlier in the day.

[Brad | DocBiohacker @DocBiohacker]

@TDekkersPhysio Worth adding: dynamic and mobility work can improve range of motion on much shorter timelines through different mechanisms (temperature, stretch tolerance, neural effects) rather than reducing tissue stiffness.

So agreed the 30-second static hold isn’t doing much.

[Brad | DocBiohacker @DocBiohacker]

@JimStoppani Worth adding: a dumbbell curl, like any exercise, only builds muscle when you keep making it a little harder over time (progressive overload). More weight is just one way; reps, sets, frequency, and tempo all count too. Stop progressing and growth stalls

[Brad | DocBiohacker @DocBiohacker]

The same buffering system exists in brain and heart, which is why it's being studied for cognitive fatigue and mood.

But the blood-brain barrier limits uptake, so those effects need higher/longer dosing and the evidence there is still thin.

Strong evidence for strength and lean mass. Promising but unproven for the brain.

[Brad | DocBiohacker @DocBiohacker]

Creatine isn't just a muscle supplement but muscle is where the evidence is strongest.

It rapidly regenerates ATP during short, intense effort.

Typical muscle dosing is 3-5g/day for saturation in ~4 weeks.

A loading phase is not required but will accelerate saturation.

[Brad | DocBiohacker @DocBiohacker]

@muscleforlife True - 2 people at the same weight can have very different visceral fat and lean mass, which is what actually drives metabolic risk

[Brad | DocBiohacker @DocBiohacker]

@KenDBerryMD Great post! Worth noting there's a dose-response relationship between ultra-processed food consumption and all-cause mortality suggestive of causality.

[Brad | DocBiohacker @DocBiohacker]

@JimStoppani Agreed! Adequate weekly volume combined with a sufficient proximity to failure are the key determinants of hypertrophy.

[Brad | DocBiohacker @DocBiohacker]

@muscleforlife Spot on! Regular physical activity helps preserve strength, mobility, cardiovascular health, cognition, and independence with aging

[Brad | DocBiohacker @DocBiohacker]

@andre_heeg True! Wearables are trend tools, not built for accurate staging. Against sleep studies, wearables detect sleep vs. wake with high sensitivity, but stage classification is substantially weaker.