Do anti-thinning shampoos like biotin or DHT-blocker formulas really regrow hair?

The honest consensus across specialist subreddits is that no shampoo regrows hair the way minoxidil or finasteride can, because contact time on the scalp is too short. What these shampoos can do is reduce breakage, support a healthier scalp environment, and make existing hair look fuller. Reviewers who report visible improvement almost always pair the shampoo with other interventions.