Collagen peptides reach the blood within one to two hours of a hydrolysed collagen drink. The changes you can see were measured in weeks: skin at 4 to 8 weeks, hair at 12 to 16 weeks, nails at 24 weeks.
- Skin shows first. Collagen density in the dermis was up after 4 weeks in one placebo-controlled trial, and hydration after 8 weeks in another.
- Hair follows. Hair thickness rose by 1.93 micrometres over 16 weeks in a trial of 44 women.
- Nails take longest. Over 24 weeks, nail growth rate rose 12% and broken nails fell 42%.
of 106 women felt the appearance of their skin improved after 8 weeks on our liquid marine collagen.
- 87%fewer fine lines and wrinkles
- 86%healthier hair
- 76%stronger nails
How long does collagen take to work?
Collagen reaches your blood within hours and shows in the studies within weeks, from 4 weeks for skin to 24 weeks for nails. The first part happens out of sight, as collagen peptides appear in the blood within one to two hours of a hydrolysed collagen drink. The wait is for the second part, once skin, hair and nails have had time to grow with that supply.
Researchers take readings at set points rather than every day. Line those readings up and you get the calendar below, which shows when each change was recorded in a study and in what order.
- Hours
Peptides reach your blood
When volunteers drank hydrolysed collagen, collagen peptides appeared in their blood and peaked within one to two hours.1
- Week 4
Skin moves first
Collagen density in the dermis is significantly higher in a placebo-controlled trial,2 eye-wrinkle volume is lower than placebo,3 and cheek elasticity is better than placebo in postmenopausal women.4 Women in our own trial began to report visible results.5
- Week 6
Hydration registers
Skin hydration is significantly above placebo in women taking fish collagen peptide,6 and is up 7.5% in the collagen group of a marine collagen drink trial.7
- Week 8
The two-month reading
Hydration is significantly improved in a placebo-controlled trial,2 and eye-wrinkle volume is about 20% lower than placebo.3 In our trial, 95% of women felt the appearance of their skin improved.5
- Week 12
Skin and hair, side by side
A marine collagen drink trial reports hydration up 13.8%, elasticity up 22.7% and a wrinkle index down 19.6% in its collagen group, and expert grading scores hair appearance higher.7 A pooled analysis of 19 trials reports at 90 days.8
- Week 16
Hair thickness, measured
In 44 women on 2.5 g of collagen peptides a day, hair thickness rose by 1.93 micrometres on average, against a slight dip of 0.99 micrometres with placebo.9
- Week 24
Nails grow it out
After 24 weeks on 2.5 g of collagen peptides a day, nail growth rate was up 12% and broken nails were down 42% among 25 participants in an open-label study.10
- After you stop
Four weeks after the last dose
Skin results were still measurable four weeks after the last dose in the trials that checked.3,4,11 For nails, the share with a clinical improvement kept rising.10
When did each change show up in the studies?
Skin changes showed up first, from week 4, then hair at 12 to 16 weeks, then nails at 24 weeks. The table sorts the same evidence by the outcome you care about most.
When each change showed up in the studies
The reading at which each study recorded a change, and the length of that study.
| Outcome | When the change was measured | Study length |
|---|---|---|
| Skin elasticity | Week 4: cheek elasticity better than placebo in a trial of 36 postmenopausal women, with 5 g of marine collagen hydrolysate a day.4 | 4 weeks, with a second check four weeks after stopping |
| Skin hydration | Week 6: significantly higher than placebo in a trial of 64 women aged 40 to 60, with 1,000 mg of fish collagen peptide a day.6 | 12 weeks |
| Wrinkles | Week 4: eye-wrinkle volume significantly lower than placebo in a trial of 114 women aged 45 to 65, with 2.5 g of collagen peptides a day.3 | 8 weeks, with a second check four weeks after stopping |
| Hair | End of a 12-week trial: the expert-graded score for healthy hair appearance had improved by 31.9% on average with a marine collagen drink, against 9.4% with placebo.7 Week 16: hair thickness up 1.93 micrometres with collagen peptides.9 | 12 weeks and 16 weeks |
| Nails | Week 24: nail growth rate up 12% and broken nails down 42% in an open-label study of 25 participants taking 2.5 g of collagen peptides a day.10 | 24 weeks |
Why does collagen take weeks, not days?
Collagen takes weeks because you are waiting for growth, and every tissue grows at its own pace. A daily portion feeds what your body builds next, and it shows once enough new skin, hair and nail has formed to notice.
- Skin is the quickest. The skin's outer layer renews in roughly 20 days in young adults, and takes more than 10 days longer in older adults.12 So the skin readings lead the timeline.
- Hair is slower. Scalp hair grows about 1 cm a month, and each hair follicle sits in the dermis.13 A month of new growth is a short length of hair, so hair studies run for 12 to 16 weeks.
- Nails are slowest. Fingernails grow about 3.47 mm a month.14 At that pace the nail study ran for 24 weeks.
assets/img/blog/hl-calendar.webpWhat results can you see from collagen after 1 month?
At 1 month, the first measured result is deep in the skin: in a placebo-controlled trial, daily collagen peptides had significantly increased collagen density in the dermis after 4 weeks, and that gain was still present at 12 weeks.2 The deep layer changes before the surface does.
The surface was not far behind. In a trial of 114 women aged 45 to 65, the lines around the eyes already measured smaller than in the placebo group at the week-4 reading.3 Our guide to collagen for wrinkles covers those studies and the skin imaging.
Elasticity has a week-4 result too, in postmenopausal women taking 5 g of marine collagen hydrolysate a day.4 We cover that life stage in collagen and menopause.
In our own trial, women taking our liquid marine collagen reported visible results in as little as 4 weeks, with further improvement by week 8.5
What does 8 weeks of collagen look like?
At 8 weeks, women in our user trial reported changes in their skin, hair and nails. That is where the trial ended: 106 women took our liquid marine collagen daily for 8 weeks, then reported what they saw.5
What 8 weeks looked like in our trial. Participants in the 8-week user trial of our liquid marine collagen, photographed before and after.
Skin led the answers: 95% felt its appearance had improved, 89% reported more moisture and glow, and 87% noticed fewer fine lines and wrinkles. Hair and nails were already in the picture, with 86% reporting healthier hair and 76% stronger nails.5
Why the studies keep going past week 8
The studies keep going past week 8 because a 2023 analysis of 26 randomised controlled trials with 1,721 participants found the hydration effect was larger when collagen was taken for more than 8 weeks. Overall, oral collagen significantly improved skin hydration and elasticity compared with placebo.15
The 12-week trials show what the extra month adds:
- Hydration keeps climbing. In a marine collagen drink trial, the authors reported it up 7.5% at week 6 and up 13.8% at week 12 in the collagen group.7
- Wrinkles and elasticity join in. Crow's-feet wrinkling and skin elasticity were significantly better than placebo at 12 weeks in women taking fish collagen peptide.6
- Wrinkle scores drop. In women aged 45 to 60 on 10 g of hydrolysed fish collagen a day, the wrinkle score fell 35% from baseline on the right side of the face.16
- Density rises. In a trial of 72 women, a drink with 2.5 g of bovine collagen peptides plus acerola extract, vitamin C, zinc, vitamin E and biotin raised skin hydration by 28.0% and skin density by 24.8% from baseline, against 9.0% and 6.8% with placebo.11
How long does collagen take to work for hair and nails?
Hair results were measured at 12 and 16 weeks and nail results at 24 weeks, longer than skin, and the studies are designed that way. Hair has readings at 12 weeks, when expert grading scored its appearance higher, and at 16 weeks, when thickness had risen by 1.93 micrometres with collagen peptides.7,9 The full evidence is in collagen for hair.
Nails had the longest study, an open-label one in which 25 participants took 2.5 g of collagen peptides daily for 24 weeks. Nail growth rate rose 12%, the frequency of broken nails fell 42%, and 80% agreed their nails looked better.10
Our own trial reported sooner. At 8 weeks, 86% of the women in it reported healthier hair and 76% reported stronger nails.5
What happens if you stop taking collagen?
Skin results were still measurable four weeks after people stopped taking collagen, in the several studies that checked again.
- Eye wrinkles. The reduction in eye-wrinkle volume was still there four weeks after the 8-week course ended.3
- Elasticity. The cheek elasticity difference in postmenopausal women was still there four weeks after stopping.4
- Hydration and density. After the 12-week bovine collagen peptide drink, results in the collagen group were still above their starting point four weeks on.11
- Nails. 64% showed a clinical improvement in brittle nails at 24 weeks, rising to 88% four weeks after stopping.10
How long did it take for the women who wrote about it?
By their own accounts, the women who wrote about it noticed their skin first, within the first month, and hair and nails over about six months. Published first-person accounts of marine collagen follow the same order as the studies.
Softer from the first month.
Over three months of daily marine collagen, her skin felt softer and smoother from month one. Plumper, glowier skin came after that.
Eleanor VousdenBeauty editor, writing in Who What Wear UK17
“My nails were the best I had ever had in my whole life.”
She began marine collagen after turning 40. Her skin was more hydrated within the first month, fine lines had almost faded by month three, and by month six her hair felt thicker and fuller.
Charlotte DormonWriting in Hip & Healthy18
“To my surprise, these worked.”
Around six months on 10,000 mg of marine collagen a day brought glowier, more even skin that held on to hydration for longer, and nails that were less brittle.
Charlotte BitmeadWriting in Stylist19
Independent first-person accounts of marine collagen published by the outlets named.
How do you make the weeks count?
Take collagen daily, take enough, take it with vitamin C and keep going past 8 weeks: those are the four habits the studies point to. The calendar runs at your body's pace, and you decide how full each week on it is.
- Take it daily. Every skin, hair and nail result on this page comes from a daily dose, so the timeline above describes daily use.
- Take enough. Those trials used between 1 g and 10 g of collagen peptides a day. One portion of Core™ contains 11,000 mg of hydrolysed marine collagen.5
- Take it with vitamin C. Vitamin C contributes to normal collagen formation for the normal function of skin.20 Each portion of Core™ has 120 mg.
- Keep going past 8 weeks. The pooled trials found a larger hydration effect beyond that point,15 and hair and nail studies ran to 16 and 24 weeks.
Questions about how long collagen takes
How long does collagen take to work?
Collagen peptides reach the blood within one to two hours. In the studies, the first skin changes were measured at 4 weeks, hydration at 6 to 8 weeks, hair at 12 to 16 weeks and nails at 24 weeks.
Can I see results from collagen in 2 weeks?
The trials here have no 2-week reading: the earliest readings that showed a change in these trials were at 4 weeks, so that is the first point with evidence behind it. The supply side is quick, with collagen peptides appearing in the blood within one to two hours of a hydrolysed collagen drink.
How long does collagen take to work for hair?
The hair studies report at 12 and 16 weeks. Expert grading scored hair appearance higher after 12 weeks of a marine collagen drink, and hair thickness rose by 1.93 micrometres after 16 weeks of collagen peptides.
How long does collagen take to work for nails?
Nail results were measured at 24 weeks in the nail study: over that time nail growth rate rose 12% and broken nails fell 42%. In our 8-week trial, 76% of women reported stronger nails.
What happens if I stop taking collagen?
In the trials that checked, skin results were still measurable four weeks after the last dose, and the share of people with improved nails rose from 64% to 88% over the same four weeks.
Does taking more collagen make it work faster?
The trials here measured results by weeks of daily use rather than by dose: they used between 1 g and 10 g of collagen peptides a day and reported the changes on the timeline above. One portion of Core™ contains 11,000 mg, so a single portion covers your day.
