The skincare industry runs on novelty. Every season brings new ingredients with promising names — phyto-something, bio-this, marine-that. Most of these will not be remembered in five years. Tretinoin has been in use since 1969 and remains the single most evidence-backed anti-aging ingredient available.
The minimalist case: if you stripped your routine to one active, tretinoin would do more than any other single ingredient.
What tretinoin does
Tretinoin (all-trans retinoic acid) is the prescription version of the retinoids found in over-the-counter products. It is significantly more potent than retinol — about 20 times more bioavailable — because OTC retinol must be converted to retinoic acid by your skin, while tretinoin is already in active form.
Clinical effects: faster cell turnover, reduced fine lines, improved hyperpigmentation, smoother texture, reduced acne. Effects are visible after three to six months of consistent use.
How to get it
In the US: a dermatologist prescription, or a telehealth service like Curology, Apostrophe, or Dermatica. Telehealth has made tretinoin accessible for $20-40/month including formulation. In other markets it is sometimes available over the counter.
How to actually use it
Start at 0.025% concentration, twice weekly. Apply to dry skin, evening only, after cleanser and toner, before moisturizer. The “retinol sandwich” technique — moisturizer, tretinoin, moisturizer — reduces irritation.
Critical: SPF every single morning. Tretinoin makes skin photosensitive. Sun damage on retinoid-using skin compounds badly.
Where PDRN fits
Tretinoin and PDRN work well as a pair — but not in the same application. Tretinoin is exfoliating and barrier-stressing; PDRN is regenerative. Alternate nights: tretinoin one evening, PDRN the next. This is the most effective minimalist anti-aging routine available without injectables.