Does Mixing Collagen With Coffee Reduce Its Absorption? A Clinical Trial Has Answers
Adding collagen hydrolysate to coffee altered some amino acid absorption but did not affect the uptake of bioactive collagen peptides — the fragments thought to deliver health benefits.
Quick Facts
What This Study Found
Dissolving collagen hydrolysate in coffee altered the absorption of individual amino acids (hydroxyproline and proline showed significant variations) compared to dissolving it in water. However, the bioactive peptides themselves (Pro-Hyp, Hyp-Gly, Gly-Pro-Hyp) were absorbed similarly regardless of whether the collagen was mixed with water or coffee — the key pharmacokinetic measures (iAUC, peak concentration, time to peak) were equivalent.
Peak concentrations of signature amino acids occurred between 60 and 120 minutes after intake. The polyphenols in coffee appear to affect free amino acid absorption but not the intact bioactive peptide fragments.
Key Numbers
360-minute monitoring period · UPLC-MS/MS measurement · peak amino acid concentrations at 60–120 min · Hyp and Pro absorption significantly altered by coffee · Pro-Hyp, Hyp-Gly, Gly-Pro-Hyp absorption equivalent in water vs coffee
How They Did This
Randomized, crossover clinical trial in healthy human volunteers. Participants received a single fasting dose of bovine collagen hydrolysate dissolved in either water or coffee. Blood samples were collected over 360 minutes and plasma concentrations of signature amino acids (hydroxyproline, glycine, proline) and bioactive peptides (Pro-Hyp, Hyp-Gly, Gly-Pro-Hyp) were measured using UPLC-MS/MS (ultra-performance liquid chromatography tandem mass spectrometry).
Why This Research Matters
Millions of people add collagen powder to their morning coffee. Coffee is rich in polyphenols, which are known to bind to proline-rich proteins like collagen. This study answers a practical question many consumers have: does mixing collagen with coffee reduce its effectiveness? The reassuring finding is that the bioactive peptide fragments — the parts thought to deliver health benefits — are absorbed just as well from coffee as from water.
The Bigger Picture
The collagen supplement market is worth billions, and adding collagen to coffee is one of the most popular ways people consume it. Understanding how food matrices affect peptide bioavailability is critical for making evidence-based dietary choices. This study adds to a growing body of pharmacokinetic research showing that collagen peptides are remarkably robust — surviving digestion and absorption even in the presence of polyphenol-rich beverages.
What This Study Doesn't Tell Us
The exact number of participants is not stated in the abstract. Single-dose fasting design doesn't capture how collagen performs with food or during repeated daily use. Only one coffee preparation was tested (variations in brew strength, temperature, and type could matter). Long-term health outcomes from collagen peptide absorption were not assessed.
Questions This Raises
- ?Would other polyphenol-rich beverages like green tea or red wine have a similar or different effect on collagen peptide absorption?
- ?Does adding milk, sugar, or fat to the collagen-coffee mixture change absorption dynamics?
- ?Do the altered free amino acid absorption patterns from coffee have any meaningful health implications?
Trust & Context
- Key Stat:
- Bioactive peptides absorbed equally in coffee vs water Despite coffee's polyphenols affecting some free amino acid absorption, the bioactive collagen peptide fragments (Pro-Hyp, Hyp-Gly, Gly-Pro-Hyp) showed equivalent pharmacokinetic profiles whether dissolved in water or coffee.
- Evidence Grade:
- Rated moderate because this is a randomized crossover clinical trial in healthy humans with objective pharmacokinetic endpoints measured by validated mass spectrometry. However, the sample size is not stated and long-term outcomes were not assessed.
- Study Age:
- Published in 2025 in Food Research International. This is very recent evidence directly relevant to the popular practice of adding collagen to coffee.
- Original Title:
- Unravelling the bioavailability of amino acids and bioactive peptides from collagen hydrolysate in coffee in healthy volunteers.
- Published In:
- Food research international (Ottawa, Ont.), 211, 116478 (2025)
- Authors:
- Virgilio, N, Schoen, C, van der Steen, B, Kleinnijenhuis, A J, van Holthoon, F L, Vleminckx, S, Silva, C I F, Prawitt, J
- Database ID:
- RPEP-13932
Evidence Hierarchy
Frequently Asked Questions
Can I mix my collagen supplement with coffee without losing benefits?
Yes, according to this clinical trial. While coffee's polyphenols altered the absorption of some individual amino acids, the bioactive peptide fragments from collagen (Pro-Hyp, Hyp-Gly, Gly-Pro-Hyp) — which are thought to be responsible for collagen's health benefits — were absorbed equally well whether dissolved in water or coffee.
Why were researchers concerned about coffee affecting collagen absorption?
Coffee contains polyphenols, which are known to bind to proline-rich proteins like collagen. Since collagen is unusually rich in proline and hydroxyproline, there was a legitimate concern that coffee could trap collagen fragments and prevent them from being absorbed into the bloodstream.
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Cite This Study
https://rethinkpeptides.com/research/RPEP-13932APA
Virgilio, N; Schoen, C; van der Steen, B; Kleinnijenhuis, A J; van Holthoon, F L; Vleminckx, S; Silva, C I F; Prawitt, J. (2025). Unravelling the bioavailability of amino acids and bioactive peptides from collagen hydrolysate in coffee in healthy volunteers.. Food research international (Ottawa, Ont.), 211, 116478. https://doi.org/10.1016/j.foodres.2025.116478
MLA
Virgilio, N, et al. "Unravelling the bioavailability of amino acids and bioactive peptides from collagen hydrolysate in coffee in healthy volunteers.." Food research international (Ottawa, 2025. https://doi.org/10.1016/j.foodres.2025.116478
RethinkPeptides
RethinkPeptides Research Database. "Unravelling the bioavailability of amino acids and bioactive..." RPEP-13932. Retrieved from https://rethinkpeptides.com/research/virgilio-2025-unravelling-the-bioavailability-of
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Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.