Written by the Nuvirox Research Team
- The characteristic “fishy” smell in many collagen supplements comes from marine (fish or jellyfish) sourcing — it's a byproduct of the raw material, not a sign of spoilage.
- Bovine and porcine collagen sources generally have a milder, less noticeable odor and taste than marine collagen, which is one practical reason many people prefer them.
- Manufacturers actively research odor-reduction processing methods, and mixing collagen into acidic or strongly flavored liquids (coffee, citrus juice) is the most common at-home fix.
Short answer: yes, it’s normal, and it’s almost always about the source material, not a defect. Collagen supplements are extracted from animal connective tissue — most commonly cow hide (bovine), pig skin (porcine), or fish skin and scales (marine). Marine collagen in particular tends to carry a distinct fishy smell and taste because of compounds naturally present in fish skin that survive the hydrolysis process. This isn’t a sign your supplement has gone bad; it’s simply what unprocessed or lightly processed marine collagen smells like.
Why does marine collagen smell fishy in the first place?
Marine collagen is prized because its amino acid structure closely resembles human collagen, and it tends to have smaller peptide sizes that some research associates with easier absorption. But the same fish skin and scale tissue that make it valuable also carry trimethylamine oxide (TMAO) and related compounds — the same class of molecules responsible for the smell of fish generally. Hydrolysis (the process that breaks collagen down into absorbable peptides) doesn’t fully eliminate these compounds, so some carryover into the final powder is common, especially in less-refined products.
Does a stronger smell mean lower quality, or the opposite?
Not necessarily either way. Smell intensity varies by fish species used, how the skins were cleaned before processing, and how much additional deodorization or flavoring was applied afterward. A 2025 review of marine collagen processing methods specifically flagged improving smell and flavor as an ongoing area of research and development in the industry — in other words, manufacturers are actively working on this because it’s a known, common complaint, not because odor-free products are already the unquestioned standard.
| Source | Recent Advancements in Marine Collagen (review, 2025) |
| Compounds implicated in odor | Trimethylamine oxide (TMAO) and related volatile compounds |
| Industry direction | Ongoing R&D into extraction methods that reduce residual odor/flavor while preserving peptide bioavailability |
What about bovine or porcine collagen — does that smell too?
Generally, bovine and porcine collagen have a much milder profile — often described as neutral or faintly savory rather than fishy — which is one of the practical (non-marketing) reasons many people who are sensitive to taste or smell gravitate toward non-marine sources. This isn’t a claim that one source is more effective; it’s purely a sensory difference tied to the raw material.
What actually helps if the smell or taste bothers you?
A few practical, low-effort fixes come up consistently in both product literature and user reports: mixing the powder into something with a strong competing flavor (coffee, citrus juice, a smoothie with berries) tends to mask it effectively; cold liquids generally carry less odor than hot ones, since heat can volatilize more of the smell-causing compounds; and capsule or tablet formats sidestep the taste/smell issue almost entirely, at the tradeoff of a lower per-serving dose than powder.
Is it ever a sign the product has actually gone bad?
Collagen powder can degrade over time, particularly if exposed to moisture or stored somewhere warm. A rancid, sharply sour, or distinctly "off" smell — different from the baseline fishy or neutral smell you noticed on first opening the container — combined with clumping or discoloration is a more reliable sign of spoilage than smell alone. If in doubt, check the expiration date and storage conditions before continuing to use a product that smells notably different than it did when new.
FAQ
Will the fishy smell go away if I let the powder sit out? No — and doing so risks moisture exposure and degradation. It’s better to mask the smell in your drink of choice than to try to air it out.
Does a stronger smell mean more collagen per serving? Not directly. Smell intensity tracks with sourcing and processing, not with the amount of protein in a scoop.
Are unscented or "flavored" collagen products actually different, or just masked? Most flavored collagen products use natural or artificial flavoring to cover the base smell rather than using a different raw material — though some do combine this with a milder-smelling source to begin with.
Is fishy-smelling collagen safe to keep taking? If it’s the ordinary marine-collagen smell you noticed from day one and the product is within its expiration date and properly stored, yes — the smell alone is not a safety signal.
Why we formulated Collagen+ Complex
We built Collagen+ Complex with everyday usability in mind — something you can actually stick with rather than dread each morning. As with all our formulas, we're continually refining based on where the research points, and we stand behind every order with our 60-day money-back guarantee — long enough to actually evaluate it the way the research says you should.
Learn more about Collagen+ Complex →Does freezing or refrigerating collagen powder help with the smell? Cold storage can slow degradation over time, ' 'but it won't meaningfully change the baseline smell of the powder itself — that's tied to the source material's inherent compounds, not ' 'temperature at the point of use.
It's also worth knowing that hydrolyzed collagen powders are processed to break large collagen molecules into smaller peptides for easier ' 'absorption, and this hydrolysis step is where some of the odor compounds either concentrate or dissipate, depending on the specific enzymatic ' 'process used by the manufacturer. This is part of why smell can vary noticeably between brands using the same base source material — ' 'it's not just about fish versus cow, but about the specific processing methods applied afterward, which most consumer labels don't disclose ' 'in detail.
Storage habits also affect smell more than most people expect. Collagen powder exposed to humidity — a bathroom cabinet near a ' 'shower, for instance — tends to clump and develop odor changes faster than powder kept in a cool, dry pantry with the lid tightly sealed ' 'between uses. This is a low-effort fix that often gets overlooked in favor of assuming the product itself is simply "strong smelling" by nature.
Capsules and tablets sidestep this whole conversation, though at the cost of a lower per-serving protein dose than a scoop of powder ' '— typically a few hundred milligrams to a couple grams per capsule versus 5–20 grams in a typical powder scoop, meaning capsule users often ' 'need several pills to match a single powder serving.
Related reading from this batch: Does Collagen Help With Bone Spurs (Osteophytes)? and Does Collagen Help With Hand Osteoarthritis?.
The bottom line
A fishy smell in a marine collagen supplement is a normal byproduct of its source material, not a red flag. If it bothers you, masking it in a flavorful drink or switching to capsules solves the practical problem without giving up on the supplement. For more on sourcing differences, see our comparison of marine vs. bovine collagen and our guide to choosing a collagen supplement.
References
- Recent Advancements in Marine Collagen: Exploring New Sources, Processing Approaches, and Nutritional Applications. PMC ID: PMC12112968.
- Skin Antiageing and Systemic Redox Effects of Supplementation with Marine Collagen Peptides. PMC ID: PMC4745978.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. This article is for informational purposes only and is not a substitute for professional medical advice.