Is It Safe To Take Marine Collagen?
Scarlett Gray
BNutrDiet (Hons), APD, SDA
Accredited Practising Dietitian with Dietitians Australia (APD200526). Accredited Sports Dietitian and Credentialled Eating Disorder Clinician. First Class Honours in Nutrition and Dietetics from the University of Newcastle.
Is it safe to take marine collagen? Everything you need to know
Marine collagen is one of the most widely studied food supplements available. Its safety profile is supported by peer-reviewed research, with multiple clinical trials reporting both efficacy and good tolerability. For the vast majority of people, daily marine collagen supplementation is safe and well tolerated. There are a small number of specific situations where additional care is warranted. For the complete picture on marine collagen and how to choose the right supplement, read our best marine collagen UK guide.
What is marine collagen made from?
Marine collagen is extracted from the skin, scales and bones of fish — typically tilapia, cod or other aquaculture-farmed species. The collagen is hydrolysed, meaning it is broken down into smaller peptide chains using enzymes. The result is a bioavailable protein with an amino acid profile similar to the collagen found in the human body. It contains no synthetic compounds, stimulants or hormones.
Are there any side effects?
Side effects from marine collagen are rare and generally mild. The most commonly reported are:
- Mild digestive discomfort in the first few days — this typically settles within a week as the gut adjusts
- Rarely, a mild taste sensitivity in those with low tolerance to fish-derived ingredients
Serious adverse effects from marine collagen supplementation are not reported in the clinical literature at standard doses. A 2020 clinical study of fish-derived hydrolysed collagen found that supplementation was safe and well-tolerated in an ageing population. Kollo Premium Liquid Marine Collagen uses Naticol® certified marine collagen peptides — a clinically tested ingredient with an established safety record.
What about long-term use and product purity?
A separate concern people sometimes raise is whether marine collagen supplements could contain heavy metals or other contaminants from the sea. A 2025 analysis of marine collagen supplements examined this directly, testing samples for toxic metals and metalloids. Only trace contents were found in fish-derived samples, and the study concluded that the marine collagen supplements investigated were safe for consumers at the recommended daily doses (5–10 g per day).
This is also where third-party certification matters. Kollo Premium Liquid Marine Collagen is Informed Choice certified, meaning every batch is independently tested for over 200 banned substances and contaminants — an additional layer of quality assurance on top of the published safety data.
Who should not take marine collagen?
Fish allergy
Marine collagen is derived from fish and is not suitable for anyone with a diagnosed fish allergy. This is the primary contraindication. A review of fish allergy sets out the relevant considerations in more detail. If you have a shellfish allergy but not a fish allergy, marine collagen derived from fish skin and scales is generally considered safe, but always consult your GP if in doubt.
Pregnancy and breastfeeding
There is insufficient clinical data on marine collagen supplementation during pregnancy and breastfeeding to make a definitive recommendation. The ingredient itself is a food-derived protein and is not known to cause harm, but as a precaution, consult your GP or midwife before starting marine collagen during pregnancy or while breastfeeding.
Prescription medications
Marine collagen is a food supplement and does not have known interactions with most medications. However, if you are taking prescription medications — particularly anticoagulants, immunosuppressants or medications for autoimmune conditions — consult your GP before starting any new supplement. Read our full guide on collagen and medication interactions for more detail.
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Shop Liquid Collagen →Is it safe to take marine collagen every day?
Yes. Daily supplementation is what the clinical research is based on — the benefits of marine collagen are dose-dependent and require consistent daily intake at the studied dose (typically 10,000mg). Intermittent supplementation produces weaker and less consistent results. A 2020 clinical trial reported that fish-derived hydrolysed collagen was safe and well-tolerated when taken daily, supporting its use for skin health in an ageing population. Many Kollo customers have been taking it daily for three or more years.
- Safe for daily long-term use at the studied dose of 10,000mg
- Informed Choice certified — independently tested for banned substances
- No known drug interactions at standard doses for most users
- Not suitable for fish allergy sufferers
- Consult your GP if pregnant, breastfeeding or on prescription medication
Kollo Health was co-founded by Jenni Falconer — TV presenter, Smooth Radio breakfast host, ten-time London Marathon runner and host of the RunPod podcast. Read her story and why she created Kollo.
