Hair growth shampoos and serums: what actually works?

Key takeaways

• A shampoo is a cleanser. Its job is a healthy, clean scalp, not regrowth.
• Medicated shampoos (ketoconazole, zinc pyrithione, selenium sulphide) help when dandruff or scalp inflammation is adding to hair fall.
• Among leave-on products, minoxidil has the strongest evidence for pattern hair loss in men and women. It is a prescription decision best made after diagnosis.
• Caffeine has one large Indian trial suggesting benefit, but more independent studies are needed.
• Plant extracts, peptides and "complexes" mostly have small, short, often manufacturer-run studies. They may help some people but should not replace proven treatment.

Can a shampoo really make hair grow?

People bring me shampoo bottles and ask, "Doctor, is this one good?" My first question back is, "How long does it stay on your head?" See, what happens is, a shampoo sits on your scalp for maybe thirty seconds to two minutes before you rinse it off. In that time it has to dissolve oil and sweat and lift away dirt. A review for dermatologists in the Indian Journal of Dermatology describes a shampoo's main function as cleaning the scalp and hair, with conditioning and helping manage scalp disorders as additional roles.

That short contact time is the main reason shampoo "growth" claims are weak. Whatever the active ingredient is, caffeine, onion, biotin or a plant extract, it has very little time to be absorbed before it goes down the drain.

What a good shampoo can do: - Keep the scalp clean so dandruff and inflammation do not add to shedding. - Reduce breakage by being gentle and pairing well with a conditioner. - Deliver an antifungal such as ketoconazole when dandruff or seborrhoeic dermatitis is present, if you leave it on for five minutes or so.

If your hair feels thicker after a "volumising" shampoo, that is a cosmetic effect on the hair shaft. It does not mean more hairs are growing.

Which serum and lotion ingredients have evidence?

Leave-on products stay on the scalp for hours, so at least an ingredient has a chance to reach the follicle. But the evidence is very uneven.

Minoxidil. The European Dermatology Forum S3 guideline, an evidence-based guideline for pattern hair loss, assessed the available treatments, and topical minoxidil is one of those with the strongest support for both men and women. It is not a cosmetic. It has side effects, needs consistent daily use, and should be started after a diagnosis confirms pattern hair loss. Read minoxidil explained.

Caffeine. A randomised multicentre study in India of 210 men with pattern hair loss compared a 0.2% caffeine leave-on liquid with 5% minoxidil over six months. The improvement in the proportion of growing hairs was 10.59% with caffeine and 11.68% with minoxidil, and the authors concluded caffeine was not inferior. Two things to notice. It was an open-label study, and it was a leave-on liquid, not a shampoo. It is a reasonable option for some people, but one trial is not the same as years of evidence.

Peptides and botanical complexes. Many serums sold in India now list trademarked blends of peptides, plant extracts or "stem cells". Some have published studies, but these tend to be small, short, combined with other treatments such as PRP, or run by the people selling the product. That does not mean they do nothing. It means I cannot honestly tell you how much they add.

How do I read a hair serum label?

This is what I would do if I were standing in the shop: 1. Find the active ingredient and its strength. "With minoxidil" or "caffeine-enriched" means little without a percentage. 2. Look for human studies, not lab or cell studies. "Clinically tested" often means tested for irritation, not for regrowth. 3. Check the study length. Hair grows about 1 cm a month. A two-week or four-week study cannot show real regrowth. 4. Be wary of before-and-after photos. Lighting, wet hair, styling and camera angle change how dense hair looks. 5. Watch for very large claims. "Regrows hair in 30 days" or "stops hair fall permanently" do not fit how hair biology works. 6. Patch test. Fragrance, essential oils and propylene glycol can irritate the scalp, and an irritated scalp sheds more.

So what should I buy?

Honestly, for most people with hair fall, a sensible routine is simple:

• A mild shampoo you like, used as often as your scalp needs. In Mumbai's humid months, that may be daily or every other day.
• A conditioner on the lengths.
• A medicated anti-dandruff shampoo two or three times a week, only if you have flaking or itch. See dandruff and hair fall.
• A leave-on treatment chosen after a diagnosis, not from an advertisement.

Here is the arithmetic I share with people. Spending Rs 1,500 a month on a new serum every few weeks, without knowing whether the cause is pattern hair loss, shedding after illness, low iron or thyroid trouble, often just delays the right treatment. Checking which blood tests matter and getting a scalp examination costs less over a year. It's about results, not about how many bottles are on the shelf.

How we approach this at Dr Tvacha

At a hair diagnosis I look at what you are already using and tell you plainly what to keep, what to stop and what to add. Many people come in with a shelf full of products, and often the plan becomes shorter, not longer. Prescription treatments are chosen only after assessment, and what you do with my advice is your call. The hair plan page explains the Rs 499 diagnosis and the treatment options at our Thane, Andheri, Bandra and Dahisar centres.

Written by

Dr Amit KarkhanisAesthetic Physician · MBBS, Dip. Dermatology (UK) · Reg. No. 2001/02/1124

Founder of Dr Tvacha, practising in Thane since 2005. Leads the weight loss and hair programmes.