Retinol: what the studies show, and the products
63 of the human studies we graded used retinol, and 27 showed an improvement. Its products are graded on the studies of every form of vitamin a. This page is educational, not medical advice.
What it does, by goalMembersThe top 5 of 15 goals
| Goal | What the studies show | Studies | Dose that worked |
|---|---|---|---|
| Improved in studies 20 studies, 13 showed an improvement, 1 pooled analysis | 20 | 0.002 % | |
| Improved in studies 19 studies, 12 showed an improvement, 1 pooled analysis | 19 | 500 mg | |
| Improved in studies 22 studies, 10 showed an improvement, 3 pooled analyses | 22 | – | |
| Improved in studies 19 studies, 7 showed an improvement, 2 found none, 3 pooled analyses | 19 | 50 mcg | |
| Improved in studies 7 studies, 3 showed an improvement, 1 pooled analysis | 7 | 0.4 % | |
| Improved in studies 3 studies, 2 showed an improvement, 1 found none | 3 | 10,000 IU | |
| Improved in studies 3 studies, 1 showed an improvement, 1 found none | 3 | 7 mg | |
| Improved in studies 3 studies, 1 showed an improvement | 3 | 18,000 IU | |
| Improved in studies 3 studies, 1 showed an improvement | 3 | 2 mg | |
| Improved in studies 1 study, it showed an improvement | 1 | – | |
| Too few studies 1 study, no clear result | 1 | – | |
| Too few studies 1 study, no clear result | 1 | – | |
| No effect in studies 5 studies, 3 found none, 1 pooled analysis | 5 | – | |
| No effect in studies 1 study, it found no effect | 1 | – | |
| No effect in studies 1 study, it found no effect | 1 | – |
Members see which goal each result is for, and the products for it. Start My 7-Day Free Trial →
Products – highest ranked firstMembersThe top 3 of 4
Dose and safetyThe dose that worked and the upper limit
The studies of retinol taken by mouth that showed an improvement gave 0.002 to 0.5 % a day.
The upper limit for adults is 3,000 mcg of vitamin a a day; above it, members see a note and are told they can take less.
Biohacker panelMembersWhat our 10 biohackers say about retinol
Questions people askMembersAnswered from the figures on this page
What is retinol good for?
Answer for members.
How much retinol a day?
Answer for members.
Can I take retinol with my meds?
Answer for members.
Members see the answers, checked against their own meds and goals. Start My 7-Day Free Trial →
Educational, not medical advice. Figures come from the human studies on PubMed we have graded; a study counts for a form when it names the form it used. Updated as new studies arrive. How we grade →