Collagen and stretch marks in pregnancy: the evidence
Collagen and stretch marks in pregnancy: the evidence
Stretch marks during pregnancy are common, normal, and largely down to genetics and the rate at which the skin is asked to stretch. Many women look at collagen as a way to support the skin during this time. Here is a balanced look at what the evidence does and does not say about collagen for stretch marks in pregnancy, what to talk to your midwife about, and how to think about it sensibly.
Does collagen prevent stretch marks in pregnancy?
There is no robust clinical evidence that taking collagen prevents stretch marks during pregnancy. Stretch marks form when the dermis is stretched faster than collagen and elastin fibres can adapt, and the strongest predictors are genetics, skin type, age and the rate of weight or bump growth, not nutrient intake. That said, marine collagen peptides supply amino acids the body uses to build and maintain skin, including glycine, proline and hydroxyproline. As part of an overall protein-adequate diet, collagen may support skin during periods of rapid stretch. It is not a guarantee, and it has not been studied as a stretch-mark intervention. Always check with your midwife or GP before adding any supplement during pregnancy. Be aware that most marine collagen products, including those based on Naticol peptides, have not been specifically clinically tested in pregnant populations, even where the underlying ingredient has a strong general safety profile.
What we know, what we don't
The collagen and elastin story
Collagen makes up roughly 75% of dry skin weight, and elastin gives it the ability to stretch and snap back. During pregnancy the skin can stretch by 30 to 50% over the bump in a matter of months, which is faster than the dermal scaffolding can fully adapt to. Where it breaks, you get a stretch mark. Our complete guide to liquid marine collagen covers the underlying biology in more detail.
Pregnancy nutrition and skin support
Skin during pregnancy benefits from the same things skin always benefits from: adequate hydration, sufficient protein, vitamin C, and zinc. The NHS already recommends a folic acid supplement and vitamin D during pregnancy. Anything else, including collagen, should be added only after a conversation with your midwife. Our women's wellness guide covers the broader nutrient picture for women navigating different life stages.
Safety, fish allergens and what to ask your midwife
Marine collagen is sourced from fish and is not suitable for anyone with a fish allergy. Quality matt
ers more than usual during pregnancy: look for products tested by Informed Choice, which screens for banned substances and contaminants, and ask your midwife specifically about the supplement you are considering. The same caution applies for the period before pregnancy, which we cover in our piece on collagen when trying to conceive.
Stretch mark prevention approaches in pregnancy
| Approach | What it does | Evidence | Watch out for |
|---|---|---|---|
| Marine collagen | Supplies amino acids for skin synthesis | Limited in pregnancy, ask midwife | Not specifically tested in pregnant populations |
| Topical oils (Bio-Oil, almond) | Supports comfort and hydration of stretched skin | Mixed for prevention, helpful for dryness | Patch test, avoid essential oils unless cleared |
| Hydration and protein from food | Foundational support for skin | Strong (general nutrition) | Hard to over-do, easy to under-do |
| Gradual, midwife-led weight gain | Slows the rate of skin stretch | Strong | Should be guided by your midwife |
How to think about collagen during pregnancy
- Speak to your midwife or GP before starting any new supplement
- If approved, choose a product registered with Informed Choice for purity
- Prioritise food-first protein, hydration, and the supplements your midwife recommends
- Topical oils can support comfort but are not proven preventatives
- Be realistic, genetics are the biggest driver of stretch marks
- Be kind to yourself, stretch marks are normal and common
Collagen and stretch marks during pregnancy is a topic where caution and honesty matter more than confident claims. Marine collagen peptides like Naticol have a strong general safety profile and Informed Choice certified products like Kollo Liquid Marine Collagen are screened for purity, but no marine collagen has been specifically clinically tested in pregnancy and no supplement is a proven preventative for stretch marks. Speak to your midwife, prioritise foundational nutrition, and treat your skin with kindness.
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. As a mum.
