Hey man, props for being proactive early — starting treatment in the early stages can make a big difference. That said, just a heads-up: buying raw minoxidil powder from sites like Alibaba, AliExpress, or IndiaMart can be really risky. Purity, contamination, and dosing are huge concerns unless you're sourcing from a pharmaceutical-grade supplier with verified lab reports (which most of those platforms don’t guarantee).
Since you're 18 and just starting to see recession, oral minoxidil (even at a low dose) + ketoconazole shampoo is already a strong combo. If that doesn’t slow it down, then looking into a well-tolerated topical anti-androgen like RU or CB-03-01 makes sense — but those are still experimental and not fully regulated.
If things continue or you're unsure about what to try next, I’d honestly recommend visiting a hair restoration clinic or dermatologist who understands male pattern hair loss in younger guys. You want to preserve what you’ve got long-term — safely.