The science

What the research says about your
skin.

Collagen is one of the most studied supplements in the world. Below are six peer-reviewed studies: what they tested, who took part, how much they took and what they found. Every one links to the original paper.

19 Randomised trials pooled in one 2021 review
1,125 People across those trials
90 Days of daily collagen for skin results in that review
6 Peer-reviewed studies on this page
SkinInternational Journal of Dermatology · 2021
1,125people

across 19 randomised controlled trials

Collagen improved skin hydration and elasticity

A systematic review and meta-analysis pooled 19 randomised, double-blind trials. People taking hydrolysed collagen had better skin hydration and elasticity, and fewer wrinkles, than those on placebo. The authors found 90 days of daily use was effective.

Who
1,125 adults aged 20 to 70
How long
Around 90 days
Dose
Varied by trial

de Miranda RB, Weimer P, Rossi RC. Effects of hydrolyzed collagen supplementation on skin aging: a systematic review and meta-analysis. Int J Dermatol. 2021;60(12):1449-1461.

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SkinSkin Pharmacology and Physiology · 2014
8weeks

to a significant improvement in skin elasticity

Better skin elasticity at a low daily dose

Women aged 35 to 55 took 2.5g or 5g of collagen peptides, or a placebo, once a day. After 8 weeks, both collagen groups showed significantly better skin elasticity than the placebo group.

Who
69 women aged 35 to 55
How long
8 weeks
Dose
2.5g or 5g daily

Proksch E, Segger D, Degwert J, et al. Oral supplementation of specific collagen peptides has beneficial effects on human skin physiology: a double-blind, placebo-controlled study. Skin Pharmacol Physiol. 2014;27(1):47-55.

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JointsApplied Physiology, Nutrition, and Metabolism · 2017
12weeks

of daily collagen in athletes with knee pain

Less knee pain during sport

Athletes with knee pain during sport took 5g of collagen peptides or a placebo every day. After 12 weeks, the collagen group reported significantly less knee pain during activity than the placebo group.

Who
139 athletes
How long
12 weeks
Dose
5g daily

Zdzieblik D, Oesser S, Gollhofer A, König D. Improvement of activity-related knee joint discomfort following supplementation of specific collagen peptides. Appl Physiol Nutr Metab. 2017;42(6):588-595.

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MuscleBritish Journal of Nutrition · 2015
15g daily

alongside 12 weeks of resistance training

More lean mass and strength from the same training

Older men with low muscle mass did 12 weeks of resistance training while taking 15g of collagen peptides or a placebo each day. The collagen group gained significantly more fat-free mass and strength, and lost more fat mass.

Who
53 men, average age 72
How long
12 weeks
Dose
15g daily

Zdzieblik D, Oesser S, Baumstark MW, Gollhofer A, König D. Collagen peptide supplementation in combination with resistance training improves body composition and increases muscle strength in elderly sarcopenic men: a randomised controlled trial. Br J Nutr. 2015;114(8):1237-1245.

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RecoveryAmerican Journal of Clinical Nutrition · 2017
2x

a blood marker of collagen production

Vitamin C and collagen before exercise

Healthy men took vitamin C-enriched gelatin one hour before a short skipping session. The 15g dose doubled a blood marker of collagen production. It's one reason we add vitamin C to every sachet.

Who
8 healthy men
How long
1 hour before exercise
Dose
5g or 15g gelatin with vitamin C

Shaw G, Lee-Barthel A, Ross ML, Wang B, Baar K. Vitamin C-enriched gelatin supplementation before intermittent activity augments collagen synthesis. Am J Clin Nutr. 2017;105(1):136-143.

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BoneNutrients · 2018
12months

of daily collagen in postmenopausal women

Bone density went up in the spine and hip

Postmenopausal women with reduced bone density took 5g of collagen peptides or a placebo every day for a year. Bone mineral density in the spine and the top of the thigh bone increased significantly in the collagen group compared with placebo.

Who
131 postmenopausal women
How long
12 months
Dose
5g daily

König D, Oesser S, Scharla S, Zdzieblik D, Gollhofer A. Specific collagen peptides improve bone mineral density and bone markers in postmenopausal women: a randomized controlled study. Nutrients. 2018;10(1):97.

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These studies used collagen peptides or gelatin from different sources, at the doses shown. They are not studies of UNFLTRD. itself, and results vary from person to person. Each UNFLTRD. sachet contains 6g of marine collagen.

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