Rosemary water has become one of the most popular hair care trends online. Before you spray it on your scalp, here is what it actually is, how it differs from rosemary oil, and what is and is not backed by research.
What is rosemary water?
Rosemary water is rosemary steeped or simmered in water, strained, and used on hair and scalp. Some versions are made at home. Others are sold in bottles, often as a mist, and may include other ingredients such as glycerin, aloe or a preservative.
It is not the same thing as rosemary essential oil, and that difference matters for the research.
Rosemary water vs rosemary oil
- Rosemary essential oil is a concentrated extract of the plant's aromatic compounds. It is strong enough to irritate skin, so it is always diluted in a carrier oil or other base.
- Rosemary water is a weak infusion. Oil does not dissolve well in water, so a simmered tea carries only small amounts of the plant's oils.
That is why you cannot assume a result from rosemary oil applies to rosemary water.
What the research shows
- A 2015 trial by Panahi and colleagues in Skinmed compared rosemary oil with 2% minoxidil in people with androgenetic alopecia. After six months, both groups showed similar increases in hair count. The rosemary group also reported less scalp itching. The study was small and not blinded, so it is useful but not conclusive.
- A 1998 trial by Hay and colleagues in Archives of Dermatology tested a blend of essential oils, including rosemary, massaged into the scalp of people with alopecia areata. More of the oil group improved than the comparison group. Because rosemary was one of several oils, the study cannot show that rosemary did the work.
We are not aware of controlled human studies of rosemary water for hair growth. Anything said about it, including by us, rests on the oil research, tradition and personal experience.
How to use it
- Apply to a clean scalp, parted into sections, with a spray bottle.
- Massage gently with your fingertips for a minute or two.
- Leave it in, or rinse after a few minutes if your hair feels heavy.
- Start with two or three times a week and adjust based on how your scalp feels.
Homemade rosemary water has no preservative and spoils quickly, so keep it in the refrigerator and use it within a week. We give a full recipe in How to Make Rosemary Rice Water for Hair.
What to look for in a store-bought rosemary water
- A preservative system. Water-based products need one, or they can grow bacteria and mold. A bottle with no preservative should be refrigerated and used fast.
- The ingredient list. Check what else is in it, especially fragrance and essential oils if your scalp is sensitive.
- Realistic claims. A product that promises hair growth is promising more than the research shows.
Who should be careful
- Patch test on your inner arm first, since rosemary can cause irritation or allergy in some people.
- Stop if your scalp itches, burns or turns red.
- If you are pregnant, have a scalp condition, or are losing hair suddenly, see a doctor first. Hair loss has many causes, some of which need treatment.
Where our spray fits
We make a fermented rice water and rosemary hair spray, so keep that in mind. It is a leave-in conditioning mist for softer, shinier hair. It contains fermented rice water, rosemary extract, keratin, biotin, aloe, glycerin and panthenol, and it is free of sulfates, silicones, parabens and added fragrance. We do not claim it grows hair. We only point to the independent research above, which is about the ingredients and not about our product.
The short version
- Rosemary water is a weak infusion and is not the same as rosemary oil.
- The best human evidence is on rosemary oil, and it is small and limited.
- Homemade versions are low-risk but spoil quickly, so refrigerate and use within a week.
- Patch test first, and see a doctor if hair loss is sudden.
Sources
- Panahi Y, et al. Rosemary oil vs minoxidil 2% for the treatment of androgenetic alopecia: a randomized comparative trial. Skinmed, 2015.
- Hay IC, Jamieson M, Ormerod AD. Randomized trial of aromatherapy: successful treatment for alopecia areata. Archives of Dermatology, 1998.
