But wait: won't your body simply digest smaller collagen peptides into single amino acids? How's that different from if you were to eat any other protein source? While it was thought that all proteins and peptides were completely broken down into their constituent amino acids in the digestive tract, recent research shows that this is not the case for collagen.

Several collagen dipeptides and tripeptides bypass complete digestion, leaving as many as 10% remaining intact as they enter the bloodstream. The body will then shuttle these hydrolysedbioactive peptides to "areas of need" (e.g., skin, joints, and gut) where they can exert their beneficial effects.

Bottom line? If your hydrolysed collagen peptides are small enough to bypass digestion (less than 3kDa in molecular weight), you needn’t worry about their efficacy.

There are tons — but let’s start with the following.

SKIN

2015 study published in the Journal of Cosmetic Dermatology:

Researchers found that women who consumed 10 grams of collagen peptides daily for 10 weeks had an 8% increase in collagen density in the dermal layer, while no increase was found in the placebo group.

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HAIR

2020 study published in Nutrafoods:

Researchers found that women who consumed 2.5 grams of collagen peptides daily for 16 weeks experienced a statistically significant increase in hair thickness, while those in the placebo group reported a slight decrease.

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NAILS

2017 study published in the Journal of Cosmetic Dermatology:

Researchers found that participants who took 2.5 grams of collagen peptides daily for 6 months found that nail growth increased by 12%, and nail breakage decreased by 42%.

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GUT HEALTH

2022 study published in JMIR Formative Research:

Researchers found that participants who took 20 grams of collagen peptides daily for 6 weeks experienced a reduction in uncomfortable digestive symptoms, including bloating.

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JOINTS

2014 study published in Agro Food Industry Hi Tech:

Researchers found that participants with knee osteoarthritis who took 6 grams of collagen peptides daily for 6 months reported an improvement of 32% in joint pain, 44% in stiffness, and 22% in function.

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