The Tretinoin Starter Guide — Everything You Need to Know

I've seen the same questions about tretinoin posted every week since I joined this forum, so I'm writing the guide I wish I had when I started.

Tretinoin is a prescription-only retinoid — the acid form of vitamin A. It's the most studied topical compound for improving skin texture, fading hyperpigmentation, clearing acne, and stimulating collagen. There is no topical ingredient with a longer or stronger evidence base. If you're serious about your skin and you're not on tret, you're leaving results on the table.

Starting out: begin at 0.025% if you can get it, or 0.05% if that's all you have access to. Apply a pea-sized amount to dry skin 20-30 minutes after washing your face. Every other night for the first month. Then every night once tolerated. You don't need to do more than that.

The purge is real. For the first 4-12 weeks your skin will likely get worse before it gets better. This isn't your skin rejecting the product — it's accelerated cell turnover surfacing congestion that was already forming under the skin. Push through it. Most people who quit tret quit during the purge and never see results.

The dry skin and peeling phase is also real. This is manageable. Use a simple, non-comedogenic moisturiser like CeraVe PM or Vanicream after applying. If you're getting severe peeling, apply moisturiser first, wait 20 minutes, then apply tret on top (the sandwich method). It reduces irritation without significantly reducing efficacy.

Sunscreen is not optional. Tretinoin accelerates cell turnover and makes your skin more UV-sensitive. If you're not wearing SPF30+ every single morning, you're actively counteracting the benefits and risking PIH. I use La Roche-Posay Anthelios SPF50+ — it's lightweight, doesn't pill under makeup or foundation, and has excellent photostability.

Common mistakes: using it around the eyes without building up slowly (yes you can use tret near the eyes, just very carefully), combining it with high-strength AHAs in the same routine (unnecessary irritation), and using physical exfoliants while you're purging (you're already turning over cells at full speed).

Realistic timeline: visible improvements in texture and tone around month 3-4. Significant changes in about 6-12 months. Full collagen remodelling benefits take 1-2 years. This is a long game. Commit to it.

Excellent guide. One thing I'd add: the vehicle matters. A lot of the tret available online comes in a gel base which is more drying and more irritating than cream-based formulations. If you're getting into tret for the first time and you're not already using prescription products, see if you can get a cream formulation like tretinoin cream 0.025% or Renova. The gel is fine for oily-skinned people who tolerate it, but I've seen so many beginners quit because they got the gel version and thought tret just wasn't for them.

Thanks for this. I'm on week 3 and my skin looks terrible right now, but reading about the purge phase makes me feel a lot better. I was genuinely about to give up. Going to push through.

Week 3 is the worst of it for most people. Your skin should start to stabilise by week 6-8. Stick to the basics — gentle cleanser, tret, moisturiser, SPF. Don't add anything new while you're purging. You'll thank yourself in 3 months.

Quick question — does it matter what time of night you apply? I've been putting it on right before bed but I've heard some people say you should apply it earlier so it has time to absorb before you hit the pillow.

Timing matters less than consistency. Tret doesn't really "absorb" in the sense that waiting longer before bed gives it more time to work — it's already binding to receptors within minutes. What matters is avoiding washing it off too soon. As long as you're not hopping in the shower an hour after applying, you're fine. Apply, moisturise, sleep, SPF in the morning.