Hey fitness nerds!

Thank you all {{active_subscriber_count}} of you!

Collagen is sold like a shortcut to younger skin.

Most of the glow people chase comes from habits that cost less than another tub of powder.

Read below! 

🧼

IN LESS THAN 10 MINUTES WE WILL COVER:

Today we separate the marketing from the trials, and what is still worth doing.

Tubs of hydrolyzed collagen promise plumper skin, fewer wrinkles, better hydration, all from one scoop stirred into your coffee. Sales in this category have exploded past several billion dollars a year globally. The evidence underneath that growth is thinner than the branding suggests.

What the trials actually show

There is a real body of research here, and it is not nothing. A 2021 systematic review in the International Journal of Dermatology pooled 19 studies and found that oral collagen supplementation improved skin hydration and elasticity compared with placebo.

Doses across these trials ranged from 2.5g to 15g a day, taken for 8 to 12 weeks. Elasticity improved by roughly 8 to 15% in several trials. Hydration measures moved by similar margins.

Most trials used skin elasticity meters and hydration probes rather than biopsies or dermatologist grading. These are proxy measures. They correlate with how skin feels and looks, but they are not the same as counting new collagen fibres under a microscope.

Sample sizes were often small, frequently under 60 participants. A large share of the research was funded directly by supplement manufacturers, including Vital Proteins and Rousselot, both of which sell the hydrolyzed collagen ingredients being tested. Industry funding does not automatically invalidate a result, but it is a known source of bias in nutrition science, and it shows up repeatedly in this literature.

Wrinkle depth data is weaker still. A handful of trials report modest reductions in wrinkle depth on the order of 10 to 20%, mostly in women aged 35 to 55, over periods of 8 to 12 weeks. Longer-term data past six months barely exists. Nobody has tracked what happens after two or three years of daily use.

The theory is that hydrolyzed collagen peptides, small chains of 3 to 6 amino acids like the compound prolyl-hydroxyproline, survive digestion intact enough to signal fibroblasts in the skin to produce more collagen and hyaluronic acid. Animal and cell culture studies support this mechanism. Human skin studies are less consistent about whether enough of these peptides actually reach the dermis in meaningful concentration.

This is the gap between plausible mechanism and proven outcome. Plenty of supplements have a believable story at the cellular level that does not translate into a measurable difference on your face.

Your body makes its own collagen constantly, and it needs specific raw materials to do it well regardless of whether you supplement.

Vitamin C is essential for collagen synthesis. It is a required cofactor for the enzymes that stabilise the collagen molecule. Deficiency causes visibly poor wound healing and fragile skin, which is why scurvy was historically identified partly through skin symptoms.

Total protein intake matters just as much. Your body builds collagen from amino acids sourced from your overall diet, not exclusively from collagen powder. Someone eating adequate protein, roughly 1.2 to 1.6g per kilogram of bodyweight, along with normal vitamin C intake from fruit and vegetables, already has the building blocks in place.

This is worth sitting with. If you are already eating enough protein and vitamin C, the marginal benefit of an extra collagen-specific supplement gets smaller.

Sunscreen has decades of strong evidence behind it for preventing the collagen breakdown that ages skin. UVA radiation penetrates deep into the dermis and directly degrades existing collagen while triggering enzymes called matrix metalloproteinases that break it down further. A landmark Australian trial published in the Annals of Internal Medicine followed over 900 people for more than 4 years and found that daily sunscreen users showed no detectable increase in skin ageing, while irregular users aged visibly more.

Topical retinoids are the other proven heavyweight. Tretinoin has been studied in randomized trials since the 1980s and consistently increases collagen production in the dermis, measurably reducing fine lines and improving texture within months. This evidence is far more rigorous than anything backing oral collagen, including actual skin biopsies showing new collagen deposition.

Sleep and smoking belong in the same conversation even though they get less attention. Chronic sleep deprivation raises cortisol, and cortisol breaks down collagen. Smoking reduces blood flow to skin and directly damages collagen and elastin fibres through oxidative stress, with visible effects on wrinkling that are well documented in twin studies comparing smokers to non-smoking identical twins.

Ranked by strength of evidence, sunscreen and retinoids sit well above oral collagen. Sleep and smoking cessation affect skin ageing through mechanisms that are arguably even more powerful, just harder to quantify in a single trial.

None of this means collagen powder is worthless. If your diet is genuinely low in protein or vitamin C, an oral collagen supplement combined with correcting those gaps could plausibly help, and the modest trial results are more believable in that context.

It may also suit someone who already has sunscreen and a retinoid dialled in and wants a low-risk addition on top. Hydrolyzed collagen has a strong safety profile and few side effects beyond occasional mild digestive upset.

Just hold the expectation honestly. The realistic outcome, based on the actual trial data, is a modest improvement in hydration and elasticity over 2 to 3 months, not a dramatic reversal of visible ageing.

If your budget or attention only stretches to one or two things, sunscreen and a retinoid outperform collagen powder on the evidence available right now.

Collagen supplements are a reasonable add-on once those basics are covered, not a substitute for them. Check your protein and vitamin C intake first, since your body may already have what it needs to make its own.

Sleep and smoking status shape your skin more than most people assume, often more than any supplement you could add.

That is the loudest signal yet. This stuff is not a passenger along for the ride. It changes what happens to you.

And the science is still young. What we can measure today is almost certainly the floor, not the ceiling.

Article

Your body already makes glycine. Turns out more of it before bed does something useful.

Researchers gave healthy adults 3 grams of glycine an hour before sleep and tracked how rested they felt afterwards.

Results held up night after night. People fell asleep faster and reported deeper, more satisfying sleep. Daytime sleepiness dropped too, even without changes to total sleep time.

Glycine works partly by lowering core body temperature. Your body needs to cool down to drift into deep sleep, and this amino acid nudges that process along. It also acts on receptors in the brain that calm nervous system activity, which helps you switch off faster.

None of this needs a prescription. Glycine sits in bone broth, meat skins, gelatin, and collagen. Supplement versions are cheap and widely sold as powder or capsules.

The catch is timing. Taking it too early in the evening seems to blunt the effect. Studies use a window of roughly 60 minutes before lights out.

This is not a sedative that knocks you out. It works quietly in the background, smoothing the transition into sleep rather than forcing it.

For anyone waking up groggy despite a full night in bed, this is a low-risk lever worth testing before reaching for anything stronger.

Fascinating Fact:

Glycine is the smallest of all 20 amino acids, small enough to slip through the blood-brain barrier with ease, which is part of why it can act on brain temperature regulation so directly.

Most ultra-processed food never even makes it near your trolley on purpose. It gets in through habit, convenience and clever aisle design. Change how you shop and you change what ends up on your plate.

The damage happens in the 7 hour gap where you eat nothing at all, land dehydrated, and write off the whole week as a rest week.

Small changes to how you shop beat any diet plan. Your trolley decides your week before you've cooked a single meal.

Same food. Same clock. Same fluids.

Your body does not care that you are 30,000 feet up. It cares that you fed it.

Lemongrass does the heavy lifting here. Pound it fresh and it turns ordinary pork mince into something that tastes like it took hours, not 20 minutes.

Butter lettuce cups keep this light and low carb. The nuoc cham style dressing ties everything together with salt, sour and a bit of heat.