10 Best Thickening Shampoos 2025 in the UK

Grow Me® Hair Growth Shampoo by Watermans offers a well-rounded solution for individuals with thinning hair, featuring high-quality natural ingredients like Biotin, Argan Oil, Rosemary, Niacinamide, and Caffeine. These ingredients are known for promoting hair growth and enhancing scalp health, which is crucial for hair thickening treatments. The shampoo is suitable for both men and women and targets the root causes of hair thinning, making it versatile for various hair types.

Additionally, it is free of sulphates and parabens, making it a safer choice for sensitive scalps. The inclusion of Rosemary provides antioxidant and anti-inflammatory benefits, which can help reduce grey hair and improve scalp health, creating an ideal environment for hair growth. The mint scent adds a refreshing touch to the hair care routine.

However, users should be aware that for optimal results, the shampoo needs to be left on the scalp for a period to allow deep penetration of nutrients, which might require a change in usual washing habits. Watermans, the brand behind this product, has a strong reputation and has received endorsements from experts like trichologists and hair surgeons, further adding to the credibility of the shampoo. With over 13,000 customer reviews and a 4.2-star rating, it is evident that many users have found this shampoo effective and satisfying. While the shampoo may offer positive results, its effectiveness can vary from person to person, and it may not work equally for everyone.

Nioxin System 4 Scalp + Hair Shampoo is a specialized thickening shampoo designed for those with colored, dry, and damaged hair experiencing advanced thinning. Its inclusion of ingredients like biotin, niacinamide, and caffeine is noteworthy, as these are known for nourishing hair roots, stimulating follicles, and strengthening hair. This makes it potentially beneficial for individuals seeking to improve hair resilience and promote a healthier scalp environment.

The product's capability to hydrate from root to tip addresses dryness while combating thinning, which can be a key concern for many users. Its gentle cleansing action removes impurities and sebum, creating an ideal environment for hair growth. The citrus scent is a pleasant bonus, adding a refreshing touch to the hair-washing routine. Nioxin is a reputable brand in hair care, particularly for thinning hair solutions, which may provide users with confidence in the product's effectiveness.

It’s important to note that this shampoo works best when used as part of the complete Nioxin System 4 regimen, which may require additional investment in complementary products like the conditioner and thickening treatment for optimal results. Additionally, while it suits various hair types like color-treated, aging, dry, and thin hair, those with different hair concerns or preferences might need to explore other options. This product could be a good fit for adults dealing with specific hair thinning issues, especially if they’re already invested in the Nioxin hair care system.