For androgenetic alopecia, minoxidil and finasteride have the strongest clinical evidence. Minoxidil stimulates follicle activity and is available without prescription in many countries. Finasteride reduces DHT — the primary hormonal driver of pattern hair loss — and is generally considered one of the most effective options for men. The most effective approach for most people combines both, alongside strong nutritional foundations and scalp health. Individual response varies significantly depending on genetics, age, and how long hair loss has been progressing.

Meaningful results typically require 4–6 months of consistent treatment, with a full assessment more reasonably made at 12 months. Hair grows slowly — roughly 1–1.5 cm per month — and follicles must complete natural growth cycles before visible changes occur. Stabilisation of hair loss is usually the first measurable sign of progress, and often occurs before visible regrowth. Patience and consistency are not optional — they are the mechanism.

In many cases, yes — particularly in earlier stages of hair loss where follicles have been miniaturised but not permanently damaged or replaced by scar tissue. Follicles that have been dormant for long periods, or that have fully atrophied, are less likely to recover. This is why early intervention generally produces better outcomes than waiting for significant visible thinning. The presence of vellus hairs (very fine, colourless hairs) at a previously affected site is a positive sign that follicles may still be active.

Androgenetic alopecia is caused by a genetic sensitivity to dihydrotestosterone (DHT), a hormone derived from testosterone via the enzyme 5-alpha reductase. DHT binds to androgen receptors in susceptible follicles and causes progressive miniaturisation — follicles shrink and produce progressively thinner, shorter hairs over time, eventually ceasing to produce terminal hair altogether. The pattern and rate of progression are largely genetically determined, though hormonal and environmental factors also play a role.

Some studies, including randomised controlled trials, have shown promising results for microneedling as a complementary hair growth intervention. It is thought to stimulate growth factors and wound-healing pathways in the scalp, and may enhance the absorption of topical treatments such as minoxidil. The evidence base is growing but not yet conclusive at the level of systematic review. It is generally considered a useful addition to — not a replacement for — evidence-based treatments, and technique and consistency are important factors in outcomes.

GHK-CU is a naturally occurring copper peptide found in human plasma, saliva, and urine. It has been studied for its roles in tissue repair, wound healing, anti-inflammatory processes, and — more recently — follicle biology. Research interest in GHK-CU for hair growth is growing, though the evidence base is still at an earlier stage than for established treatments. It is generally discussed as a complementary addition to core treatments rather than a primary intervention. For a deeper exploration of the science, visit ghk-cu.fi.

Individual studies should always be interpreted cautiously. Sample sizes, study duration, control groups, blinding, and methodology all influence how much weight to place on findings. Meta-analyses and systematic reviews — which pool and analyse multiple studies — generally carry more weight than individual trials. Animal or laboratory studies offer mechanistic insights but do not always translate directly to human outcomes. A single promising study is a reason to stay curious, not a reason to adopt something as established. HairGrowthHub aims to clearly indicate the level of evidence behind each claim throughout its guides.