More isn’t always better! While 10% does work a little better than 5%, it’s not a crazy difference—you might see 20-30% faster growth, but definitely not double. Plus, going stronger means you’re upping your chances of dealing with side effects. As for 15%, trials show it doesn’t really work any better than the 10% version. Also, it’s worth noting that 10% often requires a prescription, and 15% is just plain hard to find anywhere.