This trial aims to evaluate the efficacy, safety, and tolerability of fractional laser combined with topical exosome for hair regrowth in patients with androgenetic alopecia.

This study is expected to recruit 30 participants. The experimental group will receive fractional laser treatment combined with human umbilical cord mesenchymal stem cell exosome solution; the control group will receive fractional laser treatment combined with a placebo. Participants will receive three fractional laser treatments and will be followed up for 6 months. At each follow-up visit, hair density, diameter, vellus hair to terminal hair ratio, and adverse reactions will be assessed using trichotomy; a global photographic assessment will be performed using standardized imaging equipment.

Inclusion Criteria:

1. Male pattern baldness diagnosed according to the Norwood-Hamilton classification III-V
2. Males aged 18 to 50 years
3. Willing to provide written informed consent and possessing the ability to read, write, speak, and understand
4. Able to follow the study's treatment guidelines

Exclusion Criteria:

1. Those who have taken oral Finasteride, Dutasteride, or Minoxidil within 6 months prior to the start of the trial.
2. Those who have used any topical or systemic medications that may affect hair growth within 6 months prior to the start of the trial.
3. Those who have received phototherapy, laser therapy, exosome therapy, or hair regrowth injections (such as minimally invasive procedures) within 6 months prior to the start of the trial.
4. Those with a history of hair transplant surgery.
5. Those suffering from other systemic or scalp diseases that may affect hair growth (e.g., iron deficiency anemia, immune disorders, thyroid diseases, and syphilis).
6. Those with a history of severe inflammation, keloids, malignant tumors, or poor wound healing at the treatment site.
7. Those with other diseases that make them unsuitable for fractional laser treatment.
8. Those with a history of malignant tumors or currently undergoing treatment.
9. Participants must not undergo any cosmetic procedures that may affect scalp condition or hair growth throughout the entire trial period, including hair dyeing, perming, bleaching, scalp exfoliation, deep scalp cleansing, or any other actions that may irritate or damage the scalp.