Marine collagen for nails: what people who actually took it say

Updated on 12 November 2026 with 838 reviews from people who took British Supplements’ Clean Genuine Hydrolyzed Marine Collagen, written between June 2019 and September 2026, and 2 studies published between 2023 and 2025.

Brittle nails that split and peel, toenails that stopped growing, or a nail that never healed after it split: that’s how people came to marine collagen for their nails. Whether collagen was doing anything at all is what one Reddit member wanted to know, and one reply was about nails: six weeks in, theirs had gone from brittle, flaky stubs to long and strong. Here’s what marine collagen for nails was like for the people who took it.

We went through every review of British Supplements’ Clean Genuine Hydrolyzed Marine Collagen. Of those, 838 mention nails, written between June 2019 and September 2026 by people in the UK. Stronger nails come up most, then nails that grew, and plenty wrote about their hair alongside their nails.

If marine collagen itself is new to you, start with what marine collagen is and where it comes from.

Here’s what the 838 reviews that mention nails talk about:

Does collagen help nails?

Yes, collagen helps nails, according to Lesley A.W., who hasn’t had a broken or split nail in two months. Lesley A.W.’s is one of 838 reviews of British Supplements’ Clean Genuine Hydrolyzed Marine Collagen that mention nails. Fifteen people wrote that it made no difference, 5 of them that it’s early days.

Brittle, splitting, peeling: those are the words that keep coming up. Here’s what two people taking collagen for nails wrote:

Does collagen strengthen nails?

Yes, collagen strengthens nails, according to Gillian S., 72, who’d always had brittle nails and felt them much stronger after three weeks. Gillian S. is one of 392 people whose reviews of British Supplements’ Clean Genuine Hydrolyzed Marine Collagen talk about how strong or brittle their nails are.

Of the 15 who saw no difference, 5 wrote that their nails still break, split or peel, or got worse. Here’s what four of the 392 wrote:

What does the research say about collagen and nails?

Collagen made nails stronger, thicker and less chipped than a placebo did, by people’s own ratings. That’s according to a 90-day trial of fish collagen published in the International Journal of Research in Medical Sciences in December 2025, in 48 adults aged 18 to 45 with concerns such as brittle nails, split evenly between collagen and placebo.

By the end, the collagen group’s nail strength score had gone up 62.5%, while the placebo group’s went down 33.3%. They also reported 51.4% less chipping and nails 37.5% thicker, while the placebo group’s scores went the other way. Everyone filled in a nail questionnaire at the start, at 45 days and at 90 days, so these were people’s own ratings of their nails, not lab measurements.

Does collagen help nails grow?

Yes, collagen helps nails grow, according to Michele N., whose toenails hadn’t grown for two years and needed cutting after three months. Michele N.’s is one of 202 reviews of British Supplements’ Clean Genuine Hydrolyzed Marine Collagen that mention nails growing. One more person wrote that theirs haven’t yet. Here’s what three of the 202 wrote about collagen for nail growth:

How long does collagen take to work on nails?

Collagen took two days to six months to work on nails, according to the 241 people who took British Supplements’ Clean Genuine Hydrolyzed Marine Collagen and gave a time alongside a change in their nails. Another 5 gave a time and no change yet. Here’s how long it took, quickest first:

• Two days, for someone whose skin and hair improved too
• About three days, for someone whose nails actually felt stronger
• Just over a week, for someone whose nails haven’t broken since starting
• Three weeks, for someone who’s 72 and had always had brittle nails
• Nearly three months, for someone without a broken or split nail in the last two
• Three months, for someone whose toenails hadn’t grown for two years
• Three months, for someone who saw a massive difference in hair and nails
• Three months, for someone whose menopausal nails were splitting, tearing and not growing
• Six months, for someone who’s 75 and whose nails had got into poor condition

What does the research say about how long it takes?

Collagen took 45 days to pull nail scores ahead of placebo, at the trial’s first check. That’s according to the International Journal of Research in Medical Sciences trial. On its nail questionnaire, the collagen group’s score had gone from about 3 to about 17 by day 45, against about 6 on placebo, and reached about 23 by day 90, against about 7.

Is marine collagen safe to take for your nails?

Whether marine collagen is safe for you to take for your nails depends on what your GP or a pharmacist says. Across every review of British Supplements’ Clean Genuine Hydrolyzed Marine Collagen, 41 people wrote that they had no side effects and 28 wrote about one. Here’s what two of the 41 wrote:

If you’re over 60, so are 3 people who took British Supplements’ Clean Genuine Hydrolyzed Marine Collagen and wrote about their nails, Gillian S., 72, among them, and none of the three wrote about a side effect. Here’s what the other two wrote:

If you’re going through the menopause, so are 45 people who took British Supplements’ Clean Genuine Hydrolyzed Marine Collagen and wrote about their nails. Here’s what two of them wrote, and neither wrote about a side effect:

More of what people wrote through the menopause is on the page about collagen for menopause.

What does the research say about safety?

The research found no real difference in side effects between collagen peptides and a placebo. That’s according to a review of 4 placebo-controlled trials in 507 people, published in the Journal of Orthopaedic Surgery and Research in September 2023.

In the 90-day fish collagen trial, nobody had a side effect linked to the collagen, and blood counts and liver and kidney tests at the start and the end showed no meaningful change.

Ask your GP or a pharmacist about what to avoid while taking marine collagen if you:

• take anything for a nail or skin condition, or any other medication
• are pregnant or breastfeeding
• have an operation booked
• have a liver or kidney condition

Anyone with a fish allergy should not take it.

The pack adds three lines of its own: not to be taken by under 18s, do not exceed the recommended daily dosage, and keep out of reach of children.

What is the best collagen for nail growth?

The best collagen for nail growth is the one with reviews from people whose nails actually grew while they took it. That’s people with names and dates, not what’s printed on the pack. Here’s what three of the 202 who took British Supplements’ Clean Genuine Hydrolyzed Marine Collagen wrote:

FAQ

Is collagen good for hair and nails?

Yes, collagen is good for hair and nails, according to Lesley A.W., whose nails are the strongest they’ve ever been and whose hair is getting noticeably longer. Lesley A.W.’s is one of 632 reviews of British Supplements’ Clean Genuine Hydrolyzed Marine Collagen that mention nails and hair together. Hair has a page of its own, on collagen for hair.

Can you take biotin and collagen together?

Yes, you can take biotin and collagen together, according to Apara, who takes both. Apara is one of 47 people who took British Supplements’ Clean Genuine Hydrolyzed Marine Collagen for their nails and take biotin as well, and none of them wrote about a side effect from the two. Ask a pharmacist or your GP first if you take any other medication or supplement.