Collagen Protein: Muscle Protein Synthesis vs Collagen Synthesis, Explained (2026)

By Purpose with Presence FitnessUpdated November 6, 202611 min read

Quick answer: Collagen is a weak protein for building muscle. It has little leucine and no tryptophan, and trials in older adults found no rise in longer-term muscle protein synthesis. Whey does that job. Collagen research targets tendons, ligaments and skin, with small or industry-linked evidence. If you add it, choose a third-party-tested product.

We did not test these products ourselves. This article explains the research, then lists third-party-tested collagen products, all sourced and linked. As an Amazon Associate I earn from qualifying purchases. We are also an independent affiliate of the training program linked further down and earn a commission if you buy it, at no extra cost to you. This article is not medical advice; talk to a clinician before taking supplements if you have a medical condition, take medication, or are pregnant.

As an Amazon Associate I earn from qualifying purchases. Quick picks, each with the certification its maker or the certifier states:

Momentous Collagen Peptides (paid link): the maker says every finished batch is certified through NSF Certified for Sport, and NSF lists it.
Thorne Collagen Fit (paid link): NSF Certified for Sport, per the maker page and the NSF listing.

What is muscle protein synthesis, and how is it different from collagen synthesis?

Muscle protein synthesis (MPS) is the process your body uses to build new muscle protein from amino acids. Resistance training and a protein meal raise it. Myofibrillar synthesis, the contractile fraction, is what most studies here mean by MPS.

Collagen synthesis is a different job. Collagen is the structural protein in tendons, ligaments, skin and the connective layer around muscle. Holwerda and van Loon (2022), a narrative review, report that collagen proteins contain high concentrations of glycine (about 33%), proline (about 10%) and hydroxyproline (about 13.5%) relative to other proteins. Researchers can test collagen synthesis in people with a blood marker, PINP, the amino-terminal propeptide of collagen I, as Shaw and colleagues (2017) did.

Why is collagen a weak protein for muscle?

Two numbers explain most of it. Oikawa and colleagues (2020) tabulated grams per serving for whey and collagen supplements: leucine 4.3 for whey and 0.9 for collagen, tryptophan 0.7 for whey and 0 for collagen, and essential amino acids 15.4 for whey and 5.6 for collagen. The International Society of Sports Nutrition position stand (Jager and colleagues, 2017) describes a protein dose of 20 to 40 g, with 10 to 12 g of essential amino acids and 1 to 3 g of leucine, as the range that stimulates MPS. A collagen serving sits below that leucine range.

Tryptophan is the second gap. Paul and colleagues (2019), whose authors include collagen-industry affiliates, write that collagen protein lacks one indispensable amino acid (tryptophan) and is categorized as an incomplete protein source.

The trials agree with the chemistry:

Oikawa 2020: 22 healthy older women took 30 g of whey or collagen twice daily for 6 days. Whey raised MPS more than collagen in both the rested and exercised leg (P = 0.02). Acutely, collagen raised MPS in the exercised leg by 0.012 %/h (P < 0.01), less than whey. Over the longer term, collagen did not raise MPS above baseline.
McKendry and colleagues (2024): 31 healthy older men took an extra 50 g a day of whey, pea or collagen. MPS rose with whey and pea and, in the authors' words, remained unchanged with collagen. The funder was a pea-protein maker.
Aussieker and colleagues (2023): 45 recreational athletes took 30 g of whey, 30 g of collagen or a placebo after exercise. Only whey raised myofibrillar synthesis above placebo; collagen did not differ from whey or placebo (P > 0.05 for both comparisons). Muscle connective protein synthesis did not differ between groups (P = 0.09), for collagen or whey. The lab discloses funding from collagen makers.
Aussieker and colleagues (2025): 28 men took a blend of 25 g whey and 5 g collagen, or a placebo. Both myofibrillar and connective synthesis were higher than placebo in the rested leg, but connective synthesis was not significantly higher in the exercised leg (P = 0.11). GELITA AG, a collagen maker, co-funded it and employs an author. It tests a whey-led blend, not collagen alone.

What do the studies measured actually show?

Figures as reported; read the last column first.

Table: What do the studies measured actually show?
Study	n and population	Dose	Outcome measured	Result	Funding or limits
Oikawa 2020	22 older women	30 g twice daily, 6 d	MPS	Whey above collagen	Whey is the comparator; dairy-linked author disclosure
McKendry 2024	31 older men	50 g/day extra	Integrated MPS	Unchanged with collagen	Pea-protein maker funded; n = 10 to 11 per arm
Aussieker 2023	45 recreational athletes	30 g once	Connective protein synthesis	No difference (P = 0.09)	Single dose; collagen-maker funding disclosed
Aussieker 2025	28 men	25 g whey + 5 g collagen	Myofibrillar and connective synthesis	Higher than placebo at rest; connective not higher in exercised leg	Collagen maker co-funded
Shaw 2017	8 men	0, 5 or 15 g gelatin, 48 mg vitamin C	Blood PINP	Doubled with 15 g	Surrogate marker; tiny sample
Lis and Baar 2019	10 active men	15 g	Blood PINP	Tended to rise; no arm significant	Large variability
Jerger 2022	40 men	5 g/day, 14 weeks	Achilles tendon size	+11.0% vs +4.7%; muscle thickness +7.3% vs +2.7%	Gelita AG funded; stiffness and strength not different
Praet 2019	20 patients (pilot)	2.5 g twice daily	VISA-A score	Both groups improved	GELITA AG funded
Clark 2008	147 athletes, 97 analysed	10 g/day, 24 weeks	Joint pain	Pain when walking differed (p = 0.007)	50 excluded from analysis
Zdzieblik 2015	53 sarcopenic men	15 g/day, 12 weeks	Fat-free mass, strength	+4.2 vs +2.9 kg	Silica placebo; maker part-funded

What might collagen do for tendons and ligaments?

This is where collagen has its best case, and it is still early. It starts with Shaw and colleagues (2017). Eight healthy men completed a randomized, double-blinded crossover study. Each drink held 0, 5 or 15 g of gelatin with 48 mg of vitamin C. One hour later they did 6 minutes of rope skipping. The routine repeated 3 times a day for 3 days. Blood drawn up to 72 hours later showed that 15 g of gelatin doubled PINP, and the doubling held through 72 h. The authors add a caveat: growth factors in the fluid around tendons are roughly 100-fold lower than in blood, so how much reaches a tendon is unclear.

A follow-up was less tidy. Lis and Baar (2019) gave 10 men a placebo, 15 g of gelatin or hydrolyzed collagen, or a gummy. PINP tended to rise about 20% from baseline with gelatin and hydrolyzed collagen, but large variability meant no arm reached significance.

Two randomized trials from one research group, funded by the collagen maker Gelita AG per the paper records, looked at tendon size after training. In Jerger and colleagues (2022), 40 men did 14 weeks of resistance training with 5 g a day of specific collagen peptides or a placebo. Achilles tendon cross-sectional area rose 11.0% with collagen and 4.7% with placebo (p = 0.002). Plantar flexor muscle thickness also rose more with collagen (+7.3% vs +2.7%, p = 0.014); stiffness and strength rose in both groups with no difference. A second trial (2023) of 50 men found a larger patellar tendon area increase and the same lack of difference in stiffness and strength. The authors say the mechanisms behind the tendon size change are unknown, and stiffness did not differ.

Praet and colleagues (2019) ran a small crossover pilot in 20 people with chronic Achilles tendon problems using 2.5 g of specific collagen peptides "bi-daily" (as worded in the paper) with calf strengthening. VISA-A rose 12.6 points in one group and 5.3 in the other, so the comparison group improved too. GELITA AG funded the work.

Does collagen do anything for skin?

Proksch and colleagues (2014) randomized 69 women aged 35 to 55 to 2.5 g, 5.0 g or placebo for 8 weeks and found elasticity improved in both dose groups. Pu and colleagues (2023) pooled 26 trials with 1721 patients and found improved hydration and elasticity, while flagging biases in the included trials. de Miranda and colleagues (2021) pooled 19 studies and reported fewer wrinkles and better elasticity and hydration.

Then the funding question arrives. Myung and Park (2025) analyzed 23 trials with 1474 participants. All together, collagen improved skin hydration, elasticity and wrinkles. But studies without pharmaceutical-company funding showed no effect, and high-quality studies showed no significant effect in any category. They conclude there is currently no clinical evidence to support the use of collagen supplements for skin aging. Grimes and Mahto (2026) went further and re-analyzed the earlier meta-analyses, reporting that of the nine hydration studies in one, seven were industry funded. Neither of the two non-industry studies found significant effects, whereas four of the seven industry studies did. The independent subsets are very small, and the paper is a critique of two meta-analyses by one group. Their meta-regression found no evidence of benefit. Batool and colleagues (2026) still found improved instrumental hydration (SMD = 0.44) and elasticity (SMD = 0.62), but called apparent wrinkle gains statistical artifacts and noted high percentages of industry-funded trials.

Our read: the independent evidence for skin is weak and thin, and the positive pooled results lean on industry-linked trials.

Does collagen help joints or body composition?

Clark and colleagues (2008) gave 147 athletes with activity-related joint pain 10 g a day of collagen hydrolysate or a placebo for 24 weeks. Data from only 97 could be evaluated. Joint pain when walking improved more with collagen (p = 0.007), and the authors say future studies are needed.

Zdzieblik and colleagues (2015) studied 53 sarcopenic men about 72 years old who all did 12 weeks of guided resistance training, three sessions a week. The group on 15 g a day of collagen peptides gained 4.2 kg of fat-free mass against 2.9 kg for the silica group,. The comparator was silica, not whey. Gelita AG paid part of the costs.

Do peptides, gelatin and dose matter?

Iwasaki and colleagues (2022), in a 9-person blood study, found gelatin raised Pro-Hyp and Hyp-Gly, though free hydroxyproline absorption was lower than with hydrolysate. Holwerda and van Loon report that 15 g of gelatin produced greater peak plasma glycine, proline and hydroxyproline than 5 g, and that about 15 g may be near-maximal for amino acid absorption. The doses in the tendon, skin and joint trials above run from 2.5 g to 15 g a day. The muscle protein synthesis trials used 30 g twice daily (Oikawa 2020), an extra 50 g a day (McKendry 2024) and 30 g once (Aussieker 2023).

How does collagen fit with whey, creatine and BFR training?

Whey comes first for muscle. Oikawa 2020 found greater MPS with whey than collagen, McKendry 2024 found MPS rose with whey and pea but not collagen, and in Aussieker 2023 only whey rose above placebo, though collagen did not differ from whey or placebo. Collagen is an add-on for the connective-tissue question, not a replacement. For a protein target, use our TDEE and calorie deficit calculator.

Blood flow restriction (BFR) training loads the muscle with light weights, and a meta-analysis by Lixandrao and colleagues (2018) found hypertrophy similar to high-load training, with strength gains higher after high-load training. Collagen research aims at connective tissue, so they are different levers. If you are curious about BFR, start with our blood flow restriction training beginner guide. If you want a structured plan, the BFR Total Body Program is one option; as noted, we are an independent affiliate and earn a commission if you buy it. Our free workout plan versus paid program comparison covers the choice.

Which collagen myths does the evidence answer?

"Collagen builds muscle like whey." No. Leucine is 0.9 vs 4.3 g per serving, and MPS did not rise with collagen in older men (McKendry 2024) or in older women's longer-term measure (Oikawa 2020).
"Collagen proves itself for skin." Not independently. Myung 2025 found no effect in studies without pharmaceutical funding.
"It goes straight to your tendons." Unknown. Shaw 2017 itself says how much would reach a tendon is unclear.

How do I choose a collagen product?

Start with testing. NSF Certified for Sport says it verifies that products do not contain unsafe levels of contaminants or prohibited substances, that they contain none of 290 substances banned by major athletic organizations, and that what is on the label matches what is in the product. Informed Sport says every batch is tested for more than 285 substances prohibited in sport. Both programs describe testing for contaminants, banned substances and label accuracy; neither page claims to test whether a supplement works.

Next, read the label. Momentous states its collagen is bovine, with 10 g collagen plus 5.2 g of Fortigel and 50 mg of vitamin C per serving. Thorne Collagen Fit lists bovine collagen peptides (15 g per scoop) plus nicotinamide riboside and betaine, with no vitamin C. We did not find a marine product we could source here. Shaw gave 48 mg vitamin C in every drink, including the placebo, so that study cannot show vitamin C adds anything. The vitamin C in a product is not shown to matter. For Thorne Collagen Plus we could not confirm any certification, so we do not list it.

The picks again, in context. As an Amazon Associate I earn from qualifying purchases. See Thorne Collagen Fit (paid link). Also see Momentous Collagen Peptides (paid link).

Primary sources

See the BFR Total Body Program

Frequently asked questions

Does collagen protein build muscle?+

Not on its own. A serving has 0.9 g of leucine against 4.3 g in whey and no tryptophan. In older women collagen raised muscle protein synthesis less than whey, and in older men it did not raise it. Whey is the better pick for muscle, with collagen as an optional extra.

How much collagen did the tendon studies use?+

The tendon trials used 5 g a day for 14 weeks, and the blood-marker study used 15 g of gelatin with 48 mg of vitamin C. Doses in the tendon, skin and joint trials above range from 2.5 g to 15 g a day. The muscle trials used 30 g twice daily, an extra 50 g a day, or 30 g once.

Is collagen good for skin?+

The independent evidence is weak. Pooled analyses are positive, but one found no effect in studies without pharmaceutical-company funding, and a 2026 critique found no evidence of benefit. Independent evidence is weak, so the research does not show a visible change from a supplement.

What does NSF Certified for Sport mean on a collagen tub?+

NSF says it verifies the product has no unsafe levels of contaminants or prohibited substances and that the label matches the contents. Neither program claims to test whether a supplement works. Informed Sport is similar, testing each batch for more than 285 substances prohibited in sport.

Should I take collagen with whey or instead of it?+

Add it, do not swap. In the studies above whey raised muscle protein synthesis more than collagen. A whey and collagen blend raised synthesis versus placebo (connective synthesis only in the rested leg), but the study had no whey-only arm and a collagen maker co-funded it.