Is Collagen Safe to Take When Pregnant or Breastfeeding?

There is no randomised trial of collagen supplements in pregnancy or breastfeeding, which is true of almost every supplement, so the accurate wording is not "proven safe" but "a food protein with no trial either way": no study has looked for a problem, and none has found one. What can be said is what collagen is: a food protein, the same protein as gelatine and bone broth, foods pregnant and breastfeeding women have always eaten. The sensible position is the NHS one for any supplement that is not folic acid or vitamin D: tell your midwife or GP what you take. The cautions that do exist on supplement labels in pregnancy are about other ingredients: preformed vitamin A (retinol) in beauty blends, which the NHS says to avoid, botanical extracts with no pregnancy data, and, for marine collagen, the fish allergen.^{1, 2} Collagen for women covers the trials outside pregnancy.

• Trial evidence: none in pregnancy or breastfeeding, in either direction
• What collagen is: a food protein, digested like any other
• Protein needs: rise in pregnancy and lactation; collagen adds to complete protein rather than replacing it
• Label checks: one ingredient; no added vitamin A or botanicals; marine collagen carries the fish allergen
• Who to ask: your midwife or GP, as for any supplement

Sources checked on 29 October 2026.

Is collagen safe to take when pregnant?

No trial has studied collagen supplements in pregnant women, so the question has no trial answer. The randomised skin, joint and bone trials enrolled adults who were not pregnant, and in them collagen peptides were generally well tolerated, with a low rate of adverse events.^{3, 4} For pregnancy: discuss it with your midwife or GP before you add it. The same applies while trying to conceive or during IVF: no trial, a food protein, tell your clinic.

Hydrolysed collagen is gelatine cut into shorter chains with food enzymes, and gelatine is cooked collagen, the protein that sets a stock.⁵ Once swallowed, the peptides are digested and absorbed as short fragments and free amino acids, which appear in the blood in amounts that rise with the dose, like the protein from any meal.⁶ The Wellgard collagen guide explains what it is and what the adult trials found.

Do protein needs rise in pregnancy?

Yes. The NHS asks pregnant women to eat some protein-rich food every day, and to avoid liver because of its vitamin A.⁷ In a study of 29 healthy pregnant women, the average protein requirement was about 1.2 g per kilogram of body weight a day in early pregnancy and about 1.5 g in late pregnancy, both well above the 0.88 g used for non-pregnant adults.⁸ For a 70 kg woman that is roughly 85 g a day early on and over 100 g near term.

Collagen can carry part of that. Collagen lacks tryptophan, one of the nine amino acids the body cannot make, so it counts as an incomplete protein: it adds to complete protein rather than replacing it, and a typical diet can take up to about a third of its protein as collagen peptides before the amino acid balance suffers.⁹ How much collagen to take a day has the adult doses.

Can I take collagen whilst breastfeeding?

The position is the same as in pregnancy: there is no trial of collagen supplements in breastfeeding women, collagen is a food protein, and the people to tell are your midwife, health visitor or GP. The NHS says small amounts of what a mother takes can pass into milk, that the amounts are generally very low, and that questions go to a pharmacist or GP or to The Breastfeeding Network's factsheets.¹⁰ The fragments that reach the blood are small food-derived peptides and amino acids; nothing suggests a risk, and nothing has tested it.⁶ The NHS breastfeeding diet advice asks for protein foods every day, as in pregnancy.¹¹

Will taking collagen affect my milk supply whilst breastfeeding?

No study has measured it, so there is no evidence either way, including for the claim that it increases supply. Milk supply responds to feeding: the NHS puts it as the more you breastfeed, the more your baby's sucking stimulates your supply and the more milk you make.¹² No known mechanism links a protein food to a fall in supply.

What to check on a collagen label in pregnancy

The cautions sit in the other ingredients. Four checks:

• One ingredient. Hydrolysed collagen peptides and nothing else; blends add vitamins, minerals and extracts that each need their own check
• No preformed vitamin A. The NHS says not to take cod liver oil or any supplement containing vitamin A (retinol) in pregnancy, because too much can harm the baby's development, and retinol appears in some collagen beauty blends¹
• No botanicals. The NHS says not enough is known about herbal remedies to guarantee they are safe while breastfeeding, and the same gap applies in pregnancy¹⁰
• Source and allergens. Marine collagen is made from fish skin and scales and carries the fish allergen declaration; bovine collagen does not. Fish collagen is a recognised allergen in its own right, so a fish allergy rules marine collagen out^{14, 15}

What vitamins to take with collagen covers deliberate pairings; in pregnancy, run any of them past your midwife first. Collagen in coffee is fine inside the NHS limit of 200 mg of caffeine a day; collagen in coffee covers the detail.²

Is marine collagen unsafe in pregnancy because of mercury?

This forum warning has no source. The NHS advice on mercury is about eating fish: pregnant women should avoid shark, swordfish and marlin and keep tuna and oily fish within weekly limits, because the flesh of large, long-lived fish accumulates mercury.² Marine collagen peptides are a protein purified from skin and scales, not fish flesh, and the law sets the same residue limits for every collagen sold as food whatever the animal: Regulation 853/2004, kept in UK law, caps mercury at 0.15 parts per million, arsenic at 1, cadmium at 0.5 and lead at 5.¹³ There is no pregnancy trial of marine or bovine collagen, so neither source can be called the safer one.

What the NHS does advise taking in pregnancy

Collagen is not on the list and should never displace what is. The NHS advises 400 micrograms of folic acid a day from before conception until week 12, with a higher dose for some women on a GP's advice; 10 micrograms of vitamin D a day (vitamin D in pregnancy and breastfeeding covers it); iron only if your blood tests show you need it; and no supplement containing vitamin A.¹ Beyond that, a varied diet with protein every day, which is where collagen belongs if it has a place.⁷

What we don't know

No trial has given collagen peptides to pregnant or breastfeeding women, so nothing has been measured for the pregnancy, the baby or the milk, in either direction.⁴ Whether collagen peptides pass into breast milk has never been measured, and stretch marks, postpartum shedding and milk supply are untested. These are gaps in the evidence, not findings of harm or of safety; is there a downside to taking collagen covers the cautions that do have evidence.

Frequently asked questions

Is it safe to take collagen whilst breastfeeding?

There is no trial in breastfeeding women, so nobody can promise it; no study has measured collagen peptides in breast milk, and nothing suggests a risk.⁶ Check the label for added vitamins and botanicals, and tell your health visitor or GP what you take.¹⁰

Why should I take collagen whilst breastfeeding?

The one certain reason is protein: a 10 g serving adds 10 g of protein with no cooking. The adult trials measured skin hydration and elasticity, knee comfort and nail growth over eight weeks and longer, but none included breastfeeding women.³

Does collagen help with stretch marks in pregnancy?

No pregnancy trial has measured it. The adult skin trials measured hydration and elasticity over eight to twelve weeks; stretch marks are a different outcome and were not studied.³

Can collagen help postpartum hair shedding?

No trial has tested it. Shedding in the months after birth is common and usually temporary; the NHS says temporary hair loss can be caused by an illness, stress, cancer treatment, weight loss or iron deficiency, that it will grow back, and to see a GP if you're worried about your hair loss.¹⁶ Collagen for hair and nails covers what the hair evidence does and does not show.

How much collagen can I take when pregnant?

There is no pregnancy-specific dose because there is no pregnancy trial. The adult trials used 2.5 to 15 g a day, and a serving counts towards the protein the NHS asks for each day.^{7, 9} Agree the amount with your midwife.

Sources

1. NHS. Pregnancy vitamins and supplements. Page last reviewed 3 June 2026. nhs.uk.
2. NHS. Foods to avoid in pregnancy. Page last reviewed 15 June 2026. nhs.uk.
3. Pu SY, et al. Effects of oral collagen for skin anti-aging: a systematic review and meta-analysis. Nutrients, 2023. Meta-analysis, 26 randomised trials, 1,721 people; no conflicts declared. PubMed 37432180.
4. Bassila C, et al. European Journal of Clinical Nutrition, 2026. Systematic review, 25 randomised trials; one author employed by a health consultancy. PubMed 42342959.
5. Hong H, et al. Preparation of low-molecular-weight collagen hydrolysates (peptides): current progress, challenges and future perspectives. Food Chemistry, 2019. Review article; funding not stated on PubMed. PubMed 31382108.
6. Shigemura Y, et al. Food Chemistry, 2014. Dose-response study, 4 volunteers; one author employed by a marine-products company. PubMed 24767063.
7. NHS. Have a healthy diet in pregnancy. Page last reviewed 21 April 2023 (review overdue). nhs.uk.
8. Stephens TV, et al. Protein requirements of healthy pregnant women during early and late gestation are higher than current recommendations. Journal of Nutrition, 2015. Amino acid oxidation study, 29 pregnant women; funding not stated on PubMed. PubMed 25527661.
9. Paul C, Leser S, Oesser S. Significant amounts of functional collagen peptides can be incorporated in the diet while maintaining indispensable amino acid balance. Nutrients, 2019. Dietary modelling study; one author works for a supplement maker. PubMed 31096622.
10. NHS. Breastfeeding and medicines. Page last reviewed 7 May 2026. nhs.uk.
11. NHS. Breastfeeding and diet. Page last reviewed 15 May 2026. nhs.uk.
12. NHS. Breastfeeding: the first few days. Page last reviewed 14 September 2026. nhs.uk.
13. Regulation (EC) No 853/2004, Annex III, Section XV: collagen, requirements for finished products (assimilated GB law, checked 29 October 2026). legislation.gov.uk.
14. Kalic T, et al. Collagen, an important fish allergen for improved diagnosis. Journal of Allergy and Clinical Immunology: In Practice, 2020. Laboratory study, sera from 101 fish-allergic patients; funding not stated on PubMed. PubMed 32389794.
15. Kobayashi Y, et al. Fish collagen is an important panallergen in the Japanese population. Allergy, 2016. Laboratory study of fish-allergic patients; funding not stated on PubMed. PubMed 26785247.
16. NHS. Hair loss. Page last reviewed 24 January 2024. nhs.uk.

Spotted something out of date? Email support@wellgard.co.uk with the page address and the sentence.

This article is general information, not medical advice. Speak to your midwife or GP before adding any supplement in pregnancy or while breastfeeding.