Evidence grade: C
A meta-analysis found improved skin hydration and elasticity. For tendons, a small study found that gelatin with vitamin C before exercise raised collagen-building markers. Outcome data is still limited.
What it is
The main structural protein in skin, tendons and bone. Supplements are hydrolyzed peptides or gelatin, usually from cow, fish or chicken.
What people claim
- Smoother skin
- Healthier tendons and joints
- Stronger hair and nails
Doses used in studies
Skin studies commonly use about 2.5–10 g a day. One tendon study used 15 g of gelatin with 50 mg of vitamin C about an hour before activity.
These are amounts researchers tested, not a recommendation for you.
Who should be cautious
- People with fish, egg or beef allergies (check the source)
- Collagen is an incomplete protein, so it does not replace other protein
- Vegetarians and vegans: it is animal-derived
- Pregnant or nursing people: ask a doctor first, as safety data is limited
- Anyone taking prescription medication: check with a doctor or pharmacist for interactions
- Under 18: talk to a doctor or parent before using any supplement
Holistic and Eastern context
Bone broths simmered for hours are a staple of Chinese, Korean and many other traditional cuisines. They are a food source of gelatin.
Sources
- Hydrolyzed collagen supplementation and skin aging: systematic review and meta-analysis de Miranda et al., Int J Dermatol, 2021
- Vitamin C-enriched gelatin before activity augments collagen synthesis Shaw et al., Am J Clin Nutr, 2017
← All supplements · Laws & Research
Education only, not medical advice. Supplements are not reviewed by the FDA for safety or effectiveness before sale, and nothing here is meant to diagnose, treat, cure or prevent any condition. Talk to your doctor or pharmacist before starting any supplement, especially if you are pregnant, nursing, take medication or have a health condition.