This clinical trial aims to determine the efficacy of human umbilical cord mesenchymal stem cell exosomes (hUCMSC-sEV) in treating androgenic alopecia in young men. It will also investigate the safety of hUCMSC-sEV. The primary inquiry it seeks to address is: * Do hUCMSC-sEV demonstrate efficacy in the treatment of androgenic alopecia in young men? * Do hUCMSC-sEV safely used to treat androgenic alopecia in young men? The clinical trial has two parts. The Phase I study is a dose-escalation trial. Researchers will determine the appropriate dosage of hUCMSC-sEV. The Phase II study is a randomized controlled trial. Researchers will evaluate hUCMSC-sEV against a placebo (minoxidil tincture) to determine the efficacy of hUCMSC-sEV in treating androgenic alopecia in young men. In the phase I study, participants will be categorized into three dosage groups: A, B, and C. In Group A, one injection site will be allocated for each 1 cm² of hair loss area, delivering a dosage of 1.0×10\^8 particles per site. In Group B, the dosage will be 1.0×10\^9 particles per site. In Group C, the dosage will be 1.0×10\^10 particles per site. Participants will attend the clinic at weeks 0, 2, 4, and 6 for treatment and assessments. Participants will also attend the clinic for follow-up examinations at weeks 8, 12, and 24. In the phase II study, participants will be randomly allocated in a 1:1 ratio to two groups: the hUCMSC-sEV treatment group and the minoxidil treatment group. hUCMSC-sEV treatment group: the appropriate dose of hUCMSC-sEV for the phase II study was determined based on assessments of safety, tolerability, and preliminary efficacy from the phase I study. Participants will receive one injection site for each 1 cm² of hair loss area. Participants will attend the clinic for therapy and assessments at weeks 0, 2, 4, and 6. Minoxidil treatment group: participants will get 1 mL of minoxidil administered daily to the area of hair loss for 12 consecutive weeks. All patients will attend the clinic for follow-up examinations at weeks 8, 12, and 24.