Collagen Benefits for Men: What the Trials Run in Men Actually Show About Muscle, Tendons, Joints, Skin and Testosterone

Written by Dimitrun Irene. Updated October 28, 2026.

Collagen peptides do the same things in men as in women, but the trials that matter most for men were actually run in men, which is unusual in this field. Fifteen grams a day alongside resistance training added about 4 kg of fat-free mass in older men with sarcopenia and a significantly larger gain in young men over 12 weeks; 5 g a day accelerated recovery in Achilles tendinopathy and more than doubled the growth of the Achilles tendon's cross-section in young men lifting weights; and 10 g a day cut activity-related knee pain in athletes and active adults of both sexes. What collagen does not do for men is the part the marketing leans on hardest: it has no measured effect on testosterone, it does not treat male-pattern hair loss, and the skin trials that show smoother, better-hydrated skin were almost all run in women, so the effect in men is assumed rather than shown. This guide separates what has been tested in men from what has been extrapolated, grades each benefit by its evidence, and sets out the dose and timing that the positive trials used.

Collagen peptides are short chains of amino acids from hydrolysed collagen, absorbed into the blood and taken up by connective tissue; the mechanism is the same regardless of sex, and the basic explanation is in what collagen peptides are. What differs is the tissue men tend to care about and the tissue that fails first. Men carry more muscle, lose it later but faster after 60, and are more likely to load tendons heavily in sport, which is why Achilles and patellar tendinopathy are disproportionately male complaints. Male skin is about 20% thicker, with more collagen at any age and a steadier decline rather than the sharp post-menopausal drop women experience, so the visible-ageing benefit that drives most collagen sales matters less and has been studied less in men. And the two concerns men ask about most, testosterone and hair, have no plausible connection to collagen at all. The useful way to read the evidence is therefore by tissue, not by sex, with a note on how many men were in each trial.

The 2015 Freiburg trial is the study most often cited for collagen and muscle, and it was run entirely in men. Fifty-three men in their seventies with diagnosed sarcopenia trained three times a week for 12 weeks and took either 15 g of collagen peptides or a placebo. Both groups gained muscle and strength, as expected from training, but the collagen group gained about 1.3 kg more fat-free mass and lost about 2 kg more fat. The authors' explanation is that collagen's amino-acid profile, rich in glycine and arginine, supports the connective-tissue scaffolding inside muscle, which older muscle rebuilds poorly. A 2019 trial in 57 young recreationally active men found a smaller but still significant advantage over 12 weeks of hypertrophy training: fat-free mass rose more on collagen, and fat mass stayed flat while it rose on placebo. Two cautions belong here. Collagen is a poor stand-alone muscle protein because it lacks tryptophan and is low in leucine, so it adds to whey or food protein rather than replacing it, a point explained in collagen peptides vs protein powder. And in both trials the benefit appeared only with training; nobody has shown that collagen builds muscle in a man who is not lifting.

Tendon is almost pure type I collagen with a slow turnover, and it is the tissue where the case for peptides is most mechanistically convincing. In the 2017 crossover study at the Australian Institute of Sport, eight young men took 15 g of gelatin with vitamin C an hour before six minutes of rope skipping; the blood marker of new collagen synthesis doubled compared with placebo, and engineered ligaments grown in their serum were stronger. That is why the combination with vitamin C and a timing before loading has become standard advice, covered in collagen and vitamin C. The clinical trials follow the mechanism. In 20 patients with chronic Achilles tendinopathy, 5 g of collagen peptides a day alongside a calf-strengthening programme improved the standard symptom score by 12.6 points in three months against 5.3 on placebo, and the groups then crossed over with the same result. In 40 young men, 14 weeks of heavy resistance training with 5 g a day grew the Achilles tendon's cross-sectional area by 11% against 4.7% on placebo and thickened the calf muscle by 7.3% against 2.7%; stiffness and strength improved equally in both groups. The pattern is consistent: collagen helps tendons adapt to load, which for a runner, a lifter or a middle-aged man returning to sport is the benefit most likely to be felt.

Activity-related joint pain, the knee that aches after a run rather than the knee with osteoarthritis, has two solid trials. In 2008, 147 Penn State athletes took 10 g of collagen hydrolysate or placebo for 24 weeks and reported less joint pain at rest and during activity, with the largest effect in those with knee pain. In 2017, 139 physically active adults with knee discomfort took 5 g daily for 12 weeks and reported less pain during activity than placebo. Both trials included men and women and did not analyse them separately, so the male-specific effect is inferred rather than measured, but there is no biological reason to expect a difference. The full evidence on joints, including the osteoarthritis trials in older adults, is in collagen peptides for joints and exercise.

The skin trials are the largest body of collagen evidence and the weakest for men specifically, because almost every one enrolled women, typically aged 35 to 65, where the post-menopausal fall in collagen makes effects easiest to detect. Meta-analyses of those trials show improved hydration and elasticity and a modest reduction in wrinkle depth after 8 to 12 weeks at 2.5 to 10 g a day. Men's skin is thicker, has more sebum, and loses collagen at a steadier rate, so the same intervention would be expected to produce a smaller and later-visible change; nobody has measured it. A man taking collagen for skin is therefore relying on extrapolation. It is not an unreasonable extrapolation, the biology is shared, but it is not evidence. The trials, and what they do and do not show, are in collagen peptides for skin, hair and nails.

The doses that produced results in the male trials were 15 g a day for muscle and body composition, 5 to 15 g for tendons, and 5 to 10 g for joints, taken every day rather than only on training days, for at least 12 weeks. Timing matters most for tendon work: the collagen-synthesis study dosed 30 to 60 minutes before exercise, and tendon trials have followed that pattern, so taking the day's dose with vitamin C before training is the evidence-based habit. For muscle, the trials took the dose after training or with a meal, and the difference is probably small. Nothing suggests a benefit from more than 15 to 20 g, and the practical ceiling and the few side effects are covered in can you take too many collagen peptides. Bovine type I and III peptides, the form used in nearly all of these trials, are described in bovine collagen peptides, and the practical routine in how to take collagen peptides.

Men whose only goal is skin should set modest expectations, and men hoping for hormonal or hair effects should save their money. What a realistic 12-week result looks like is in collagen before and after, and the timeline by goal in how long collagen peptides take to work.

For lifters and runners, what the studies show for connective tissue is in collagen for tendons and ligaments.

For men, collagen peptides have better evidence than for women on the one goal most men care about, muscle and tendon, because the key trials were run in men: 15 g a day with resistance training added fat-free mass in both older and younger men, and 5 g a day improved tendon adaptation and tendinopathy symptoms. Joint pain from activity has good mixed-sex evidence. Skin benefits are real in women and untested in men. Testosterone, hair and libido effects do not exist. Take 10 to 15 g daily, with vitamin C before training if tendons are the target, for at least three months, alongside, not instead of, complete protein and the training that makes it work.

This article summarizes published trials for general information. It does not recommend any product.