Verbatim response from Perplexity
If your hair is thinning in your twenties, the treatments with the best evidence are minoxidil and, for men, finasteride; both can slow loss and sometimes regrow hair, but they only work while you keep using them.[1][2][6][13][16] The most effective next step is usually a dermatology visit to confirm the cause, because treatment depends on whether this is pattern hair loss, a nutrient deficiency, thyroid disease, stress-related shedding, or traction from hairstyles.[1][12][18]
What actually works most consistently:
- Minoxidil: Available over the counter and widely recommended for pattern hair loss; it can slow thinning and promote some regrowth, but results usually take months and it must be continued to maintain benefit.[1][2][6][13][16]
- Finasteride: A prescription option for men only that lowers DHT and can slow or stop male pattern hair loss; it also has to be continued to keep the effect.[2][3][13][16]
- Treat the underlying cause: If blood tests show iron, thyroid, or other deficiencies, correcting them can improve shedding over time.[2][3][12]
- Hair practices that reduce breakage/traction: Avoid tight styles, harsh chemical processing, and aggressive scalp handling, especially if the thinning is from traction or breakage rather than true follicle loss.[2][3][12][16]
Options that may help but have weaker evidence or are usually add-ons:
- Microneedling with minoxidil may add benefit for hereditary hair loss.[2][12]
- Low-level laser therapy (LLLT) and PRP are used when first-line treatment is not enough, but they are generally considered adjuncts rather than the main treatment.[5][6][12]
- Supplements only help if you have a deficiency; taking them without a deficiency is not a proven fix.[3][8][12]
A practical approach:
- If you’re male: ask a dermatologist about minoxidil 5% and finasteride.[1][2][13]
- If you’re female: minoxidil is the main evidence-based starting treatment, and a doctor can check whether an antiandrogen or another option is appropriate.[6][16]
- In either case: ask for evaluation of ferritin/iron, thyroid, B12, vitamin D, and other causes if the thinning started suddenly or is diffuse.[2][3][12]
What usually does not reliably stop genetic thinning by itself:
- “Hair vitamins,” shampoos, and most cosmetic serums unless they’re addressing a real deficiency or breakage.[3][7][8][13]
- PRP, laser caps, and supplements as stand-alone replacements for minoxidil/finasteride.[5][6][12][13]
If you want, I can help you narrow this down by male vs female pattern loss, how the thinning looks, and whether it started suddenly or gradually.