Check before you startThis one has documented interactions with medication classes where the consequences are serious. If you take any prescription medicine, run it past a pharmacist before starting.
How long to take it
Ongoing only with malabsorption or a very low vegetable intake. Otherwise not needed at all.
Who it's actually for
People with fat malabsorption, cystic fibrosis, or diagnosed deficiency.
Safe upper limit
Verified3,000 mcg RAE / 10,000 IU per day (preformed retinol)
Preformed retinol is genuinely toxic in excess — liver damage, bone thinning, and birth defects. Beta-carotene does not carry the same risk.
Adult UL confirmed at 3,000 mcg RE/day. EFSA sets a stricter 1,500 mcg guidance level for post-menopausal women specifically.
Interactions to know about
- Retinoids — Isotretinoin, acitretin
- Blood thinners / antiplatelets — Warfarin, apixaban, rivaroxaban, clopidogrel, aspirin
Other supplements:
Run your full list through the interaction check.
Practical notes
- In pregnancy, avoid retinol supplements entirely unless prescribed.
- Beta-carotene supplements raised lung cancer risk in smokers in large trials — smokers should avoid them.
- Check your multivitamin; retinol stacks quietly.