Collagen for men: what it actually does (and what it doesn't)

Collagen is sold mostly to women, which is odd, because some of the strongest trial evidence for collagen peptides comes from studies in men: muscle and strength, joint discomfort in athletes, and tendon rehab. An earlier version of this page claimed collagen fixes hair loss, "leaky gut", inflammation and low energy. It doesn't, and we've taken those out. Here's what collagen can do for men, with the trials.

What collagen does in a man's body

Collagen is about a third of your total protein and the main structural material in tendons, ligaments, cartilage, bone and the deeper layer of skin. Production falls from your mid-20s onward and the decline is fairly steady in men (women see a sharper drop around menopause). The practical result over decades: stiffer joints, slower recovery from training, thinner skin. A collagen supplement is hydrolysed collagen peptides, which absorb easily and act as both building blocks and signals for those tissues.

The 4 things with evidence in men

1. Muscle and strength, with training. The clearest trial: 53 men aged over 65 with low muscle mass did resistance training 3 times a week for 12 weeks, half with 15g of specific collagen peptides a day, half with placebo. The collagen group gained more lean mass, lost more fat mass and got stronger than the placebo group doing the same training. Collagen is not a complete protein and won't build muscle on its own; alongside training and normal protein intake, it added something. More in Collagen for athletes.

2. Joint discomfort from activity. A 24-week trial in 147 college athletes (men and women) at 10g a day found less joint pain at rest and during activity than placebo. A 12-week trial in 139 active adults at 5g a day found less knee discomfort during activity. A third trial at 10g found no difference. Modest, real in 2 of 3, and it takes 12 weeks or more. Full picture in Collagen for joint health.

3. Tendon rehab. 20 athletes with Achilles tendinopathy did a standard loading rehab programme for 6 months, with 2.5g of specific collagen peptides or placebo. The collagen group improved faster and returned to running sooner. Small, but a proper design.

4. Collagen synthesis around exercise. Young men given 15g of gelatin with vitamin C an hour before a short bout of skipping showed roughly double the blood markers of collagen synthesis compared with placebo. A mechanism study, not an injury trial, but it's the basis for taking collagen before training.

Where the evidence is thinner for men

Skin. The skin trials (less wrinkle depth, better elasticity at 2.5g a day over 8 weeks) were done almost entirely in women. The biology is the same, so the result probably carries over, but there's no large trial in men to point to. Details in Does collagen actually work for skin?

Hair. Male pattern hair loss is driven by genetics and the hormone DHT, and there is no trial showing collagen slows it or regrows hair. Treatments with evidence for that are prescription ones; talk to a GP or dermatologist. What collagen may do is support the hair you have: it supplies the amino acids hair is partly built from, and some people (including the owner of this business) report faster, thicker growth. That's experience, not evidence, and we label it as such.

What we took out, and why

• "Supports a healthy gut / leaky gut / IBD." No human trial. Explained in Can you take collagen and probiotics together?
• "Reduces inflammation." Trials that measured inflammation markers found no change. See Does collagen reduce inflammation?
• "Improves metabolism and energy." Collagen is a protein with about 4 calories a gram, like any protein. It doesn't raise energy levels.
• "Minimises the risk of future fractures." There is 1 trial showing better bone density in post-menopausal women at 5g a day over a year. Nothing in men, and nothing on fractures.

How to use it

• Training for muscle: 15g a day, after training, on top of your normal protein. 12 weeks minimum.
• Joints or a tendon that keeps flaring: 5g to 10g a day, ideally 30 to 60 minutes before you load it, with a source of vitamin C. 12 weeks minimum.
• General top-up: 10g a day in your morning coffee. It's tasteless and dissolves clear.

Frequently asked questions

Is collagen different for men and women?
No. Same protein, same products. Marketing splits it; biology doesn't.

Does collagen affect testosterone?
No evidence either way. It's a food protein, not a hormone or a hormone precursor.

Can I take it with creatine or whey?
Yes. Collagen is tasteless and dissolves cold, so it goes straight into the same shake.

How much per day?
Match the goal: 2.5g skin, 5g to 10g joints, 15g muscle. The comparison is in Which collagen should I use?

The studies

• Zdzieblik D et al. (2015). Collagen peptide supplementation in combination with resistance training improves body composition and increases muscle strength in elderly sarcopenic men. British Journal of Nutrition 114:1237–1245. Read it free →
• Clark KL et al. (2008). 24-week study on the use of collagen hydrolysate as a dietary supplement in athletes with activity-related joint pain. Current Medical Research and Opinion 24:1485–1496. View →
• Zdzieblik D et al. (2017). Improvement of activity-related knee joint discomfort following supplementation of specific collagen peptides. Applied Physiology, Nutrition, and Metabolism 42:588–595. View →
• Praet SFE et al. (2019). Oral supplementation of specific collagen peptides combined with calf-strengthening exercises enhances function and reduces pain in Achilles tendinopathy patients. Nutrients 11:76. Read it free →
• Shaw G et al. (2017). Vitamin C-enriched gelatin supplementation before intermittent activity augments collagen synthesis. American Journal of Clinical Nutrition 105:136–143. Read it free →
• König D et al. (2018). Specific collagen peptides improve bone mineral density and bone markers in postmenopausal women. Nutrients 10:97. Read it free →

This article is general information, not medical advice. If you have a medical condition or take medication, speak to your doctor before taking any supplement.

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