Benefits
Skin elasticity, hydration and dermal density
In three placebo-controlled trials in women, 5 to 10 g a day of bovine collagen peptides for 8 to 16 weeks improved some skin measures more than placebo: elasticity and hydration with CollaSel PRO, and dermal density in the other two. Elasticity did not differ in those two trials, and hydration did not differ in one. Makers supplied, funded or co-wrote all three.
Skin texture and wrinkle volume
In a 16-week trial in 87 women, 5 g a day of hydrolyzed bovine collagen with 80 mg vitamin C improved skin roughness and reduced wrinkle volume and depth around the eyes more than placebo. The study products were made by a supplement company that co-funded the trial, and vitamin C was part of the product.
Joint comfort and function scores
In adults with knee, hip or ankle osteoarthritis, three placebo-controlled trials of bovine collagen peptides found lower WOMAC pain and function scores than placebo after 8 to 13 weeks, including a 160-person trial of 10 g a day of CollaSel PRO. Peptide makers ran or funded all three, and none studied people without joint disease.
Patellar tendon size with resistance training
In 20 middle-aged men lifting weights twice a week for 12 weeks, 30 g of bovine collagen hydrolysate with vitamin C after each session increased patellar tendon size and resistance to stretching more than placebo. Muscle size and strength gains did not differ between groups, and the trial was small.
Mechanism of action
Absorption of collagen peptides
In a small crossover study, single 10 g doses of collagen hydrolysates from fish, pig and cattle all raised free and peptide-bound hydroxyproline in the blood, with comparable uptake of free hydroxyproline across sources. This shows that some di- and tripeptides are absorbed intact; it did not measure any health outcome, and the maker funded it.
Peptide signaling idea
A leading idea is that hydroxyproline-containing peptides absorbed from collagen act as signals to skin and connective tissue cells, not only as building blocks. The authors of one bovine skin trial linked their results to the product's high hydroxyproline content and small peptide size. This remains a hypothesis that the trials did not test directly.
Clinical trials
Randomized, double-blind, placebo-controlled trial of 10 g a day of CollaSel Pro, type I and III peptides from bovine hide with no other ingredients, or maltodextrin for 8 weeks; one author works for the supplier, Sel (Demir-Dora et al. 2024, J Clin Med)
112 healthy women aged 35 to 60 analyzed (57 collagen, 55 placebo) of 120 enrolled.
At week 8, skin elasticity (p = 0.017), hydration (p < 0.001) and a crow's feet roughness score (p < 0.001) were better than with placebo. Facial sagging improved from baseline with collagen but did not differ from placebo. 43 adverse events were recorded in 19 participants, most often nausea and constipation; 95 percent were mild and none were serious.
Randomized, double-blind, placebo-controlled three-arm trial of 5 g a day of hydrolyzed bovine collagen with 80 mg vitamin C, the same with 30 mg hyaluronic acid, or placebo, taken as a syrup for 16 weeks; funded by the Slovenian Research and Innovation Agency and Tosla d.o.o., which produced the study products (Žmitek et al. 2024, Nutrients)
90 healthy women aged 40 to 65 enrolled; 87 completed (30 collagen with vitamin C, 28 with hyaluronic acid added, 29 placebo).
With collagen and vitamin C, dermal density rose 16.3 percent at 16 weeks (p < 0.001 versus placebo), skin roughness improved 9.6 percent (p < 0.001) and wrinkle volume fell 13.8 percent versus placebo. Dermal thickness, skin elasticity and hydration did not differ from placebo, and adding hyaluronic acid gave no extra benefit.
Randomized, double-blind, placebo-controlled trial of 5 g a day of LISAVEI bovine type I collagen peptides or maltodextrin for 12 weeks, then a 4-week washout; both drinks held the same small amounts of vitamins C and E; three authors are employees of Shanghai Meifute Biotechnology; registered as NCT06847035 after the trial had ended (Wang et al. 2025, J Cosmet Dermatol)
83 healthy women randomized (41 collagen, 42 placebo); 77 completed.
Dermal density, skin hydration and transepidermal water loss improved more than with placebo at 12 weeks (p < 0.05), and the changes held through the washout. Skin firmness also improved, but overall skin elasticity (R2) did not differ from placebo and the epidermis did not change. No adverse reactions were reported.
Randomized, double-blind, placebo-controlled trial of 10 g a day of CollaSel PRO, type I and III peptides from bovine hide with no other ingredients, or maltodextrin for 8 weeks; registered as NCT05369780; the supplier, Sel, and a contract research organization employed two of the authors (Demir-Dora et al. 2025, J Clin Med)
160 adults with knee, hip or ankle osteoarthritis, mean age 52, 80 per group.
WOMAC pain, stiffness and function scores for the knee and hip were lower, and ankle (AOFAS) scores higher, than with placebo at weeks 4 and 8 (p < 0.001). 45 of the 46 adverse events recorded were mild and none were severe.
Double-blind, randomized, placebo- and active-controlled five-arm trial over 90 days of 2.5, 5 or 10 g a day of Wellnex Type J bovine collagen peptides, 10 g of conventional bovine collagen peptides, or 10 g placebo; the product belongs to Nitta Gelatin, which employed most of the authors, and the first 100 participants to finish were analyzed (Devasia et al. 2024, Cartilage)
100 adults with knee osteoarthritis analyzed across five arms.
WOMAC, pain scale, quality of life and physician-rated change scores improved more than with placebo in all four peptide arms (p < 0.05). WOMAC fell by an average of 26 to 44 points in the peptide arms versus 5.7 on placebo, and 2.5 g of Type J matched 10 g of the conventional peptides. The cartilage breakdown marker CTX-II and an MRI knee score also improved versus placebo. Adverse events were judged unrelated to the products.
Double-blind, placebo-controlled randomized trial with a pork skin peptide arm, a bovine bone peptide arm and a placebo arm over 13 weeks; the first author worked for Nitta Gelatin India; dose and group sizes are not given in the abstract read for this page (Kumar et al. 2015, J Sci Food Agric)
Adults diagnosed with knee osteoarthritis.
WOMAC, pain (VAS) and quality of life scores fell from baseline in both the porcine and the bovine bone peptide arms while the placebo group did not change, and the abstract reports all three scores significantly lower in the peptide groups than placebo at week 13 (P < 0.01), without separate between-group figures for each arm.
Double-blind randomized trial of 30 g of hydrolyzed collagen from bovine connective tissue with 50 mg vitamin C, or 30.5 g maltodextrin with 50 mg vitamin C, after each of two weekly lower-body resistance sessions for 12 weeks; the authors reported no specific funding and no conflicts (Nulty et al. 2025, Eur J Sport Sci)
20 recreationally active men aged about 47 (9 supplement, 11 placebo).
Patellar tendon cross-sectional area rose 6.8 versus 1.2 mm2 (p = 0.027), and tendon k, a measure of resistance to stretching (p = 0.009), and Young's modulus (p = 0.018) rose more than with placebo. Squat 10-repetition maximum, isometric quadriceps torque and thigh muscle thickness rose in both groups without a group difference.
Randomized, double-blind, placebo-controlled parallel trial of 10 g of bovine Peptan twice a day or maltodextrin for 7 days before and 2 days after 150 drop jumps; funded by Rousselot, which supplied both products, and two authors were Rousselot employees (Clifford et al. 2019, Amino Acids)
24 recreationally active men.
Muscle soreness, a main outcome, did not differ significantly from placebo (p = 0.071), although it was lower at 48 hours. Countermovement jump height recovered better at 48 hours (p = 0.050). Maximal strength, pressure pain threshold, mood, inflammation markers and the bone turnover markers CTX and P1NP did not differ from placebo.
Double-blind, placebo-controlled trial of 25 g of protein as bovine collagen hydrolysate or dairy protein, or an energy-matched placebo, taken right after 30 minutes of downhill running and once daily for 3 days; funded by the New Zealand Ministry of Business, Innovation and Employment (Barclay et al. 2024, Nutrients)
33 males, 11 per group.
Downhill running caused soreness, lost jump height and force, and raised creatine kinase and inflammation markers, but there were no group or interaction effects for any outcome: the bovine hydrolysate did no better than placebo or dairy protein.