Rosemary & caffeine for hair – what does research say?

Rosemary and caffeine have long been used in hair care – but it is only in recent years that research has begun to take them seriously. Two independent studies published in 2025 now give us a clearer picture of what these ingredients can actually do for the hair and scalp.

Rosemary – from folk remedy to clinical study

Rosemary has been used in hair care for generations. But what for a long time was based on tradition and experience has now been supported by more rigorous research. A double-blind, randomized, placebo-controlled clinical study published in Cureus in 2025 investigated the effect of a rosemary-based formula on hair growth over 90 days.

What makes the study particularly interesting is the method – phototrichography, an objective and reproducible measurement method that does not rely on subjective assessments.

Study 1 – Cureus 2025: Rosemary-based formula in a double-blind clinical study

Over 90 days, the effect of a rosemary-based formula on hair growth was measured. The results showed clear changes compared to the placebo group:

• Hair thickness increased by almost 70%
• Hair density improved by 32%
• Hair loss decreased by over 40%

Source: Patel, S. et al. – Cureus, 2025. PubMed ID: 40656290

It is also worth mentioning that a comparative study already in 2015 showed that rosemary performed at a level comparable to minoxidil 2% – a prescription medication – when it came to hair growth. The new 2025 study confirms and further deepens that picture.

Caffeine – more than just a stimulating substance

Topical caffeine – that is, caffeine applied directly to the scalp – has been studied for its ability to affect the hair follicles and the hair growth cycle. The mechanism described is that caffeine counteracts the effects of DHT – a hormone linked to hair loss – by stimulating the proliferation of the hair follicles and extending the growth phase.

Study 2 – Systematic review 2025: Topical caffeine and hair growth

A systematic review published in 2025 reviewed the collected scientific literature on topical caffeine and its effect on hair growth. All reviewed studies pointed in the same direction – that topical caffeine has a positive impact on the activity of the hair follicles.

Source: Systematic review – Journal of Cosmetic Dermatology, 2025

Why we combine rosemary and caffeine

When we developed our Rosemary & Caffeine shampoo, it was precisely that combination of research and function that formed the basis for the choice of ingredients. Rosemary for the scalp environment and the activity of the hair follicles. Caffeine to support the hair's natural growth cycle.

We also combined them with:

• Rice protein – strengthens the hair strand structure, up to 36% more volume after 5 washes
• Mung beans – supports the hair's natural growth cycle
• Red clover – contributes to a calmer and more balanced scalp

This is what we actually believe in

We have chosen rosemary and caffeine because the research is clear – not because they are trendy. We have chosen rice protein because the study results are concrete. We have chosen mung beans and red clover because they fulfill a function that nothing else in the formula does.

It is not chance that determines what ends up in our shampoo bars. It is a conscious choice based on what the ingredients can actually do – for the scalp, for the hair strand, and for the hair in the long term.