To start, retinol is just one of many forms of synthetic vitamin A derivatives. It also happens to be one of the most common forms because it's usually well tolerated on all skin types. And there are other versions, too — like formulas featuring its plant-based cousin bakuchiol. (Note you always want to start slow with lower concentrations and patch test on your wrist before fully adopting it into your routine.) As for what the ingredient actually does for your skin? It combats breakouts, fine lines, and wrinkles by increasing cell turnover and sloughing off dead skin cells in the process. That said, it's not quite that simple — it depends on the formula itself. Which is why we've rounded up seven retinol must-haves and what they're specifically formulated to do. So whether you're on the lookout for a night cream that'll help lighten stubborn dark spots or you have sensitive skin and need an extra-gentle version, here's how to navigate the sometimes-overwhelming skin-care aisle, ahead.