Hair loss is undesirable for many men—and women—because one's hairstyle is often closely tied to their self-confidence. And while some people embrace it, others wish they could regrow their lost strands. Now, researchers reporting in Nano Letters have used artificial intelligence (AI) to predict compounds that could neutralize baldness-causing reactive oxygen species in the scalp. Using the best candidate, they constructed a proof-of-concept microneedle patch and effectively regenerated hair on mice.