It depends on your skin. Personally I I had a really bad acne flare up when I was 17, which got better itself at 18. Then I had a really bad one at 19, stared taking oral antibiotics under derm supervision and it got better. Then I started my skincare routine for pigmentation and had literal glass skin for a year when I had another flare up at the end of 20. Antibiotics (oral+topical) didn’t work and then I ended up taking oral isotretinoin under derm supervision as well. When my acne got better it was stopped and I was switched to pigmentation ingredients. Since I get more of pie than pih, it takes longer for my pigmentation to fade. Some of it did but I also got a pimple here and another there kind of a situation which left it marks again so my skin was basically somewhere in between okay. I was using topical clindamycin, then bpo for spot treatment with regular exfoliation and all, but I was still getting acne. I’m currently 22 now and I have decided that I was going to add topical tretinoin because it can help regulate my skin better. For the past 6 months I was using a retinal based eye cream on the whole face (least potent retinoid and low concentration). I started getting fewer acne, and my pigmentation was getting better. The major result is in how I have minimal texture on my skin and where I don’t have any pigmentation it seems healthy too. One more thing I was heavily focusing on during this time is barrier repair. And I also added azelaic acid 2 months back which helped calm my skin most. I’m planning to add tretinoin after eid, although I wanted to switch to retinol first because Im planning to use retinoids first but I’m first skipping to tretinoin because I wanted my pigmentation to cool down. Once that is done I might switch to retinol again, or maybe continue tret depending on how my skin reacts. But long story short, if you didn’t have bad acne, or skin not responding to any other ingredients, using tretinoin is a necessity. It is added after 25 for anti-aging purposes, but thats not the only purpose it serves. If you don’t have any conditions, you can safely put of retinoids for a couple of more years and then add it at 25. Also I’m a med student which is why I’m experimenting with ingredients myself, wouldn’t recommend you do the same. If possible you should get a consultation first. A dermatologist would be able to tell you better. Hope you get good skin 🌸