Collagen supplements are everywhere. The marketing is relentless: drink collagen and your skin glows, your joints heal, your hair thickens. Most of this is wishful thinking. But buried under the hype is genuine science showing that hydrolysed collagen peptides do work for certain outcomes in women over 35—particularly once oestrogen begins to decline.
What Collagen Actually Is
Collagen is the most abundant protein in your body. It's the structural scaffold of your skin, bones, tendons, ligaments, and cartilage. There are at least 16 types, but three dominate in supplements:
- Type I: skin, bone, tendons. 90% of your skin's protein structure.
- Type II: cartilage, primarily. The collagen that deteriorates in osteoarthritis.
- Type III: skin, blood vessels, internal organs. Works synergistically with Type I for skin elasticity.
Most commercial supplements are hydrolysed collagen (also called collagen peptides)—the full collagen molecule is broken into amino acid chains small enough to absorb. This is what matters: unhydrolysed collagen (regular gelatin) passes through your gut mostly unabsorbed.
The Oestrogen Connection
Here's why collagen matters more for women over 35: oestrogen directly regulates collagen synthesis.
Your fibroblasts—the cells that produce collagen—express oestrogen receptors. When oestrogen is present, fibroblasts actively produce collagen. As you age and particularly as you approach perimenopause and menopause, oestrogen declines. Collagen production plummets. Your skin loses elasticity and firmness. Your joints become stiffer. Your bones become more brittle.
This isn't cosmetic vanity. Skin elasticity decline accelerates around 35–40 in women because oestrogen drops measurably during this window. Bone loss accelerates at menopause. Joint stiffness and pain increase. These are real biological changes, not signs of failure.
Supplementing collagen doesn't replace falling oestrogen. But it provides the raw material that your fibroblasts need to make collagen when they do get the signal to do so. It's a foundational support, especially paired with resistance training (which itself stimulates collagen synthesis).
What the RCTs Actually Show
Skin elasticity and appearance:
Proksch E et al. (2014) in Skin Pharmacology and Physiology randomised 69 women (average age 53) to either 2.5g hydrolysed collagen daily or placebo for 8 weeks. The collagen group showed measurable improvements in skin elasticity (measured by biomechanical testing) and a self-reported reduction in eye wrinkle depth. This is one of the larger, better-controlled trials. The effect is real but modest—not a facelift, but a noticeable improvement.
Other trials (Asserin et al., 2015; Bolke et al., 2019) show similar results: 8–12 weeks of 2.5–10g hydrolysed collagen improves skin hydration, elasticity, and reduces wrinkle appearance in women over 40. The effect sizes are small to moderate.
Joint pain and function:
Shaw G et al. (2017) in the American Journal of Clinical Nutrition examined 24 resistance-trained women and found that those who took 15g hydrolysed collagen post-workout had significantly greater increases in muscle protein synthesis and collagen deposition in their tendons compared to placebo. This is important: collagen supplementation doesn't just sit inert. Combined with training, it stimulates local collagen synthesis, particularly in stressed tissues (tendons, ligaments).
For joint pain specifically, trials on people with osteoarthritis show mixed results. Some show benefit, others don't. The strongest evidence is for Type II collagen (specific to cartilage) rather than the Type I/III in most skin-focused products. If you have joint pain, this matters for product selection.
Body composition in women:
Jendricke P et al. (2019) examined collagen supplementation in postmenopausal women and found that those taking 15g daily with resistance training for 12 weeks had greater lean mass gains and fat loss compared to those who trained but didn't supplement. The effect was modest but measurable.
Dosing and Timing
The evidence supports 10–15g hydrolysed collagen peptides daily with adequate vitamin C (the critical cofactor for collagen cross-linking and stability).
When to take it matters:
Shaw's study above showed that collagen taken post-workout, combined with vitamin C and carbohydrate (to spike insulin), maximised collagen deposition. But the pre-sleep timing is also popular—your body repairs tissues during sleep, and providing the building blocks then makes physiological sense. There's less direct evidence for pre-sleep but it's not wrong.
Practical approach: take 10–15g hydrolysed collagen with 100–200mg vitamin C and a meal (or post-workout carbs) either post-workout or before bed. Consistency matters more than exact timing.
Types: Bovine vs Marine
Marine collagen: sourced from fish. Smaller peptide size, theoretically better absorption. More expensive. Taste is often less "fishy" when processed well.
Bovine collagen: from cattle. Slightly larger peptides but still hydrolysed. More cost-effective. No absorption difference is clinically meaningful at standard doses.
For women over 35 not specifically targeting joint pain, the difference is minimal. Pick based on cost and tolerance. If you have environmental or ethical preferences, marine might appeal more.
Practical UK Product Recommendations
- Revive Active Collagen: Type I and III, with added vitamin C, relatively affordable, widely available in UK supermarkets
- Ancient + Brave Grass-Fed Collagen: high-quality bovine, good mixability, bit pricier but good value
- Bare Biology Marine Collagen: genuine marine (from wild-caught fish), small peptide size, pricey but effective
All are evidence-based, not marketing fluff. Check the label: you want at least 10g per serving and vitamin C included (or add your own).
What Collagen Won't Do
Collagen is not a complete protein. It's low in tryptophan (affects mood and sleep) and methionine (needed for connective tissue integrity and methylation). You can't replace whole food protein with collagen. Use it as a supplement, not a replacement.
If you're eating 1.6–2g protein per kg bodyweight from complete sources (meat, fish, eggs, dairy, legumes), adding collagen is smart. If you're undereating protein overall, fix that first.
The Bottom Line
For women over 35, particularly those in perimenopause or beyond, hydrolysed collagen peptides have legitimate research support for skin elasticity, joint resilience, and training-driven body composition. The effects are modest, not miraculous. But they're real.
Take 10–15g daily with vitamin C, combine it with resistance training, and give it 8–12 weeks. If your skin looks clearer, your joints feel better, or your training recovery improves, keep going. If nothing changes, you're not missing something crucial—collagen is a nice-to-have, not essential.
Related Guides
Seb covers nutrition and metabolic health for active adults over 35. He writes for fuel-optimal.co.uk based on peer-reviewed research and works with clients across the UK to build sustainable eating strategies for long-term health and lean mass.