Do Collagen Supplements Interact with Medications?
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.
Do collagen supplements interact with medications?
Herbal remedies, vitamins and minerals can be excellent for your overall health — but they can sometimes cause problems for people on medications. One well-known example is garlic supplements interacting with anticoagulants: the interaction can increase the risk of excessive bleeding in people already on blood-thinning medication. So it's a fair question to ask about any new supplement: does collagen interact with medications?
What is in collagen supplements?
To think about whether collagen might interact with medications, it helps to know what's actually in the supplement. Drug interactions generally happen on a compound-to-compound basis.
Marine collagen supplements like Kollo contain hydrolysed collagen peptides derived from fish, alongside supporting nutrients like vitamin C and a B vitamin complex. Collagen is a protein, so it consists of amino acids — the same building blocks found in the protein content of everyday food. A 10g daily dose of collagen contributes to your overall protein intake, but it doesn't turn a normal diet into a high-protein one on its own.
Is there evidence collagen affects medications?
The honest position based on the current research: there is no direct clinical evidence that collagen supplementation negatively interacts with common medications. Collagen is a food-derived protein, and it's generally treated by the body in the same way as protein from your diet.
That said, "no direct evidence" doesn't mean every possible combination has been formally studied. If you're on prescription medication for any condition, a five-minute chat with your GP or pharmacist before starting is genuinely worthwhile — they can look at your specific situation and any newer information in their prescribing guidance.
Is collagen a blood thinner?
This one comes up regularly, particularly from people on anticoagulant medications. It's worth understanding what collagen actually does in the body.
Collagen plays a role in normal blood clotting. When a blood vessel is injured, collagen in the vessel wall becomes exposed. Platelets bind to this exposed collagen, become activated, and help form a blood clot to stop bleeding. That's the physiology inside the body — it's an essential and normal process for wound healing.
Taking a collagen supplement doesn't necessarily make your blood clot more easily. The hydrolysed collagen peptides in a supplement are broken down during digestion into amino acids, which are absorbed and used by the body across many tissues. If you're on blood-thinning medication, though, this is exactly the kind of situation where a conversation with your GP makes sense before adding anything new — not because collagen is known to interfere, but because your care team is the right person to make that call for your situation.
Collagen and thyroid medication
Thyroid conditions are common and many people take daily medication such as levothyroxine (for hypothyroidism) or thionamides (for hyperthyroidism). Currently, there is no evidence that collagen supplementation interferes with thyroid medications.
Thyroid medications can be sensitive to timing and to what you take them with, so as with any new supplement, mention it to your GP or pharmacist so they can advise on how it fits with your existing routine.
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Many collagen supplements contain more than just hydrolysed collagen. Kollo, for example, includes vitamin C and a B vitamin complex (B1, B5, B6, B12) alongside the collagen peptides and l-lysine. These additional nutrients are generally very safe and well tolerated at supplement doses. If you're on medication that specifically interacts with vitamins (for example, some blood-thinning medications interact with vitamin K, though vitamin K isn't in Kollo's formula), it's worth mentioning the full ingredient list to your GP or pharmacist.
What can we conclude?
The honest answer is that there is very little evidence of collagen supplements causing serious medication interactions. Collagen is a food-derived protein and is well tolerated by most people. That said, "no direct evidence" isn't a guarantee, and your GP or pharmacist is always the right person to check your specific situation against your specific medications and medical history.
Is Kollo a trustworthy brand?
Kollo uses Naticol® marine collagen — a patented ingredient with a fully traceable supply chain, sourced from sustainably certified fisheries and produced through clean enzymatic hydrolysis. Every batch is Informed Choice certified — independently tested for over 250 potentially harmful substances before release. Full ingredient details are available on each product page, and if you have specific questions about whether Kollo fits alongside your current medications, our team can be reached through the contact page (though the definitive advice on medication compatibility should always come from your GP or pharmacist).
Frequently Asked Questions
Do collagen supplements interact with medications?
There is no direct clinical evidence that collagen supplementation causes negative interactions with common medications. Collagen is a food-derived protein and is generally well tolerated. If you take any regular medication, please speak to your GP or pharmacist before starting a new supplement so they can advise on your specific situation.
Is collagen a blood thinner?
Collagen plays a role in normal blood clotting inside the body — platelets bind to collagen exposed at the site of a blood vessel injury as part of clot formation. Taking a collagen supplement doesn't necessarily make blood clot more easily, as the peptides are broken down and absorbed as amino acids. If you're on blood-thinning medication, speak to your GP before starting any new supplement.
Can I take collagen with thyroid medication?
There is no evidence that collagen supplementation interferes with thyroid medications like levothyroxine. Thyroid medications can be sensitive to what you take alongside them, so mention any new supplement to your GP or pharmacist so they can advise on how it fits with your existing routine.
Can I take collagen with blood pressure medication?
There is no direct clinical evidence that collagen supplementation affects blood pressure medications. As with any new supplement while on prescription medication, a conversation with your GP is the right first step.
Should I stop my medication if I start taking collagen?
No. Do not stop or change any prescribed medication without speaking to your GP first. Supplements are meant to sit alongside — not replace — the medical care your doctor has recommended.
For the complete picture on liquid marine collagen — dose, sources, research and how to choose the right supplement — read our complete guide to liquid marine collagen.
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.
