The Best Hair Serums for Growth — Including the Viral Rapunzel Hair Syrup

Best Hair Growth Serum for Hair Growth

Finding a hair serum that genuinely delivers on its promises isn’t easy — but the right formula can make a real difference to thickness, growth rate, and scalp health. We’ve tested the serums that beauty editors, dermatologists, and TikTok’s most obsessive hair communities keep recommending, and these five have earned a permanent spot in our routine.

Whether you’re dealing with thinning edges, post-partum shedding, or simply want longer hair faster, there’s something here for every hair concern — including the Rapunzel Hair Syrup, the viral pre-wash oil that’s quietly become one of the best-selling hair growth products in the UK.

1. Hair Syrup Rapunzel

Best for: Pre-wash scalp nourishment – Loved on TikTok and Instagram, Hair Syrup Rapunzel is a cult-favourite pre-wash oil treatment designed to promote hair growth from the root. Packed with rosemary, peppermint, and argan oil, this serum stimulates blood flow to the scalp and nourishes hair follicles.

Why we love it:

• 100% natural ingredients
• Ideal for all hair types, especially dry or damaged
• Smells delicious and works as a weekly scalp detox

How to use: Apply to dry scalp before washing, massage in, and leave for at least an hour (or overnight) before shampooing.

2. Chāmpo Pitta Growth Serum

Best for: Lightweight, Ayurvedic hair stimulation – This modern Ayurvedic brand is a favourite among beauty editors. The Chāmpo Pitta Growth Serum blends caffeine, turmeric root extract, and red clover to energise the scalp and reduce hair thinning. It’s silicone-free, fragrance-free, and non-greasy — perfect for daily use.

Why we love it:

• Inspired by Ayurvedic haircare
• Strengthens hair from the root
• Quick-absorbing and easy to layer under other products

How to use: Massage a few drops into your scalp daily — no need to rinse.

3. The Ordinary Multi-Peptide Serum for Hair Density

Best for: Budget-friendly results – One of the best-selling hair serums for hair growth, The Ordinary’s peptide serum helps improve density, volume, and scalp health. With ingredients like caffeine and Redensyl, it’s a powerful yet affordable option for anyone starting a hair growth journey.

Why we love it:

• Incredible value for under £20
• Visible improvements with consistent use
• Suitable for men and women

How to use: Apply a few drops at night directly to the scalp and massage in.

4. Grow Gorgeous Hair Growth Serum Intense

Best for: Fine or thinning hair – This cult Grow Gorgeous Hair Growth Serumserum uses a complex of caffeine, Chinese skullcap, and hyaluronic acid to support scalp circulation and hydrate the roots. It’s clinically proven to increase the thickness of individual hair strands by up to 13%.

Why we love it:

• Luxurious texture and scent
• Great for postpartum hair thinning
• Visible results in 8 weeks

How to use: Use daily on dry or towel-dried hair, concentrating on the scalp.

5. Kérastase Genesis Advanced Scalp & Hair Serum

Best for: Luxurious salon-quality care – A staple in French haircare routines, Kérastase Genesis Advanced Scalp & Hair Serum is ideal if you’re dealing with brittle hair or slow growth. With plant-based stem cells and ceramides, it fortifies hair from the root and improves shine and resistance.

Why we love it:

• Premium feel and fragrance
• Great for heat-styled or coloured hair
• Strengthens strands and improves texture

How to use: Apply 2-3 pipettes to towel-dried hair 2–3 times a week.

Which Hair Serum for Hair Growth Is Right for You?

Whether you prefer a nourishing pre-wash oil like Hair Syrup Rapunzel or a high-tech daily serum like Chāmpo, choosing the right hair serum for hair growth depends on your hair type and routine. For best results, be consistent and pair your hair serum for for hair growth with a healthy diet, gentle haircare, and scalp massage.