The safest way to make homemade rosemary oil for hair is to mix a few drops of rosemary essential oil into a carrier oil such as jojoba or coconut. The other route is to infuse crisp, fully dried rosemary in a carrier oil, then strain it and keep it in the refrigerator. We cover both methods below, along with dilution, application, storage and an honest look at what the evidence says about hair growth.
TL;DR
- Use dried rosemary, never fresh, for an infused oil. Moisture in fresh herbs can let botulism bacteria grow in oil.
- For the faster method, dilute rosemary essential oil in a carrier oil at roughly 1%, which is about 6 drops per 2 tablespoons. Patch test first.
- Massage it into the scalp, leave it on for a few hours or overnight, and wash it out. Expect to wait months before judging anything.
- Evidence is limited. One small 2015 trial compared rosemary oil with 2% minoxidil, but it is not proof that rosemary oil regrows hair for everyone.
- Skip it if you are pregnant or breastfeeding, and see a dermatologist if your shedding is sudden or patchy.
Table of Contents
- Infused oil vs. diluted essential oil: two different products
- Why you should only use dried rosemary
- Method 1: Warm-infused rosemary oil
- Method 2: Diluted rosemary essential oil
- Which carrier oil should you choose?
- How to apply it, and how long to leave it in
- Safety: who should be careful
- Storage: how long does homemade rosemary oil last?
- What the research actually says about rosemary oil for hair
- How to tell whether it is working
- Our perspective
- Track your results with MyHair
- Mistakes that ruin a homemade batch
- FAQ
- Sources
Infused oil vs. diluted essential oil: two different products
People use "rosemary oil" for two quite different things, and recipes online mix them up all the time.
Infused rosemary oil is a carrier oil, often olive oil, that has soaked up some plant compounds from dried rosemary leaves. It is mild and can usually be used as is. Its strength is unpredictable, because it depends on how much herb you used and how long it steeped.
Rosemary essential oil is a steam-distilled concentrate. It is far stronger, so it must always be diluted in a carrier oil before it touches your scalp. Cleveland Clinic notes that essential oils are highly concentrated and have to be mixed with another oil or water before use, and that even diluted oils can irritate skin or cause blisters and rashes.
Here is how the two compare in practice.
| Infused oil | Diluted essential oil | |
|---|---|---|
| What you need | Dried rosemary, carrier oil | Rosemary essential oil, carrier oil |
| Time | 30 to 60 minutes (warm method) or up to a month (sun method) | Under five minutes |
| Strength | Mild, varies batch to batch | Consistent, set by your dilution |
| Shelf life | Short, refrigerate | Longer, but see storage notes below |
| Main risk | Bacterial growth if herbs are damp | Skin irritation if too strong |
If you want a predictable product, the diluted essential oil is the easier one to control. If you want something gentle and kitchen-simple, the infusion works, provided you follow the safety rules in the next section.
Why you should only use dried rosemary
Many top-ranking recipes tell you to simmer fresh sprigs in olive oil. We would not do that. Herbs sitting in oil create a low-oxygen, low-acid environment, and that is the setting in which Clostridium botulinum can grow if there is moisture present. Washington State University Extension advises that unacidified herb-in-oil mixtures made at home must be refrigerated and used within 2 to 4 days, or frozen. The University of Georgia Extension likewise calls botulism a serious hazard in home food preservation and urges people to follow researched guidance.
Those pages are written about food, but the chemistry does not change because the oil is going on your scalp. We treat a hair oil with the same caution as a salad oil.
Three rules follow from this:
- Use only rosemary that is completely dry and crisp. If a leaf bends or feels damp, dry it longer.
- Refrigerate the finished oil.
- Make small batches and discard them within days rather than weeks.
Method 1: Warm-infused rosemary oil
This is the quickest infusion, and it takes under an hour.
You need:
- 2 tablespoons of dried rosemary leaves
- 1 cup of olive oil (or another carrier oil)
- A small heavy saucepan, a fine strainer or cheesecloth, and a clean glass jar
Steps:
- Crush the dried rosemary lightly between your fingers or in a mortar to help release its oils. Check that every piece is dry.
- Combine the rosemary and oil in the saucepan.
- Warm on the lowest heat for 30 to 60 minutes. The oil should barely shimmer, never bubble or smoke.
- Let it cool completely.
- Strain through a fine strainer or cheesecloth into a clean, dry jar. Press the herbs to get the last of the oil out.
- Label the jar with the date and put it in the refrigerator.
The oil will turn slightly cloudy and thicken in the cold. That is normal for olive oil. Let a small amount come to room temperature before use.
The slow sun-infusion version
Some people put dried rosemary and oil in a sealed jar on a sunny windowsill for up to a month. It works, but a month is a long time for a plant-in-oil mixture to sit at room temperature. We prefer the warm method plus refrigeration, since you can control the process and keep the batch small.
Method 2: Diluted rosemary essential oil
This is the version most people actually want when they search for a homemade rosemary oil for hair growth, because the amount of rosemary in each drop is the same every time.
You need:
- 2 tablespoons (30 ml) of carrier oil
- About 6 drops of rosemary essential oil
- A small, clean glass bottle, ideally dark
That ratio gives roughly a 1% dilution, a common starting point for scalp use. Add the carrier oil first, then the drops, cap the bottle and shake or swirl for a few seconds.
Do not scale up the drops because you want a stronger effect. More essential oil raises your odds of a rash. It does not make the oil work better.
Some recipes online call for 5 to 10 drops in a full cup of oil. That is a much weaker blend, closer to 0.1% to 0.2%, and it is gentle but it also contains very little rosemary. Pick one dilution, stick with it and note how your scalp responds.
Which carrier oil should you choose?
Cleveland Clinic names coconut oil and jojoba oil as carriers that can dilute rosemary oil and help prevent skin irritation. Olive oil is the common choice for infusions because it is already in most kitchens. Here is how we think about the three.
- Jojoba oil. Light and non-greasy on the scalp, and it rinses out more easily than most. A good first choice if your hair is fine or gets oily fast.
- Coconut oil. Solid at cool room temperature, melts on contact with skin. Some people find it heavy, and it can be hard to wash out of fine hair.
- Olive oil. Inexpensive and easy to find, and it makes a good infusion base. It is thicker, so it needs a thorough shampoo. Our guide to olive oil for hair growth goes deeper on what it can and cannot do.
If you are comparing options beyond these, we also break down natural oils for hair growth and which ones hold up to scrutiny.
How to apply it, and how long to leave it in
The application advice that comes from clinicians is simple. Cleveland Clinic says to massage a diluted formulation into the scalp, since putting oil only on the hair shaft offers little benefit.
Our routine:
- Patch test first. Dab a little diluted oil on a small area of scalp, or behind the ear, and wait 24 hours. Cleveland Clinic specifically suggests testing first, particularly if you have fine hair or atopic dermatitis.
- Part your hair in sections and apply a small amount to the scalp with your fingertips.
- Massage for a few minutes. Use the pads of your fingers, not your nails.
- Leave it on for at least a few hours. Many people apply it in the evening and wash it out in the morning. If you sleep in it, protect your pillowcase with a towel.
- Shampoo thoroughly. Oil left on the scalp can attract dirt and clog follicles, so do not skip the wash.
How often? Clinicians say it can be used daily or several times a week, but consistency over several months is what matters. We would start with two or three times a week and see how your scalp feels before going daily.
Can you leave homemade rosemary oil in your hair between washes?
We do not recommend leaving it in for days. A homemade oil has no preservatives, and it will sit on your scalp, mixing with sweat and sebum. Wash it out after a night, or after a few hours at most.
Safety: who should be careful
A natural oil is still an active ingredient. A few points we take seriously:
- Dilute every time. Never put undiluted rosemary essential oil on your scalp.
- Watch for reactions. Stop if you notice redness, burning, itching, blisters or a rash.
- Pregnancy and breastfeeding. Cleveland Clinic says rosemary oil is not recommended during either.
- Sensitive scalps. If you have atopic dermatitis, eczema or psoriasis, talk to your dermatologist before trying it.
- Keep it out of your eyes and away from children and pets.
We also like to point readers to our guide on essential oils for hair loss, which covers how other oils compare on safety. For a cautionary example of a less familiar oil, see how we patch test carrot seed oil before trusting any growth claim.
Storage: how long does homemade rosemary oil last?
Shorter than most recipes admit. Food-safety guidance for home-made herb-in-oil mixtures is to refrigerate them and use them within 2 to 4 days, or freeze them. We follow that for any infused oil, and we make only what we will use in a few days.
Practical habits:
- Use a clean, dry jar and a clean dry spoon or dropper every time.
- Write the date on the label.
- Pour out a small amount at a time rather than dipping fingers into the jar.
- Throw it away if it smells sour, looks cloudy in a way it did not before, or grows anything.
- Freeze extra infused oil in an ice cube tray and thaw a cube when you need it.
A diluted essential-oil blend contains no plant material, so it avoids the moisture problem, but it can still go rancid over time. We would still keep it in a cool, dark place and make a fresh small bottle regularly.
What the research actually says about rosemary oil for hair
This is where expectations need a reality check.
The best-known study is a 2015 randomized comparative trial of people with androgenetic alopecia. It assigned 100 participants to either rosemary oil or 2% minoxidil for six months. The results suggested rosemary oil performed comparably, and that is the source of most of the headlines.
But look at what the trial was and was not. It was small. It compared rosemary oil with the lower 2% minoxidil strength and did not include a placebo group. We are not aware of it being repeated in a large multi-center trial. A single small study is a reason for curiosity, not a promise.
Clinicians are cautious as well. Cleveland Clinic advises patients to keep expectations realistic. Hair growth varies from person to person, results are not guaranteed, and long-standing hair loss is less likely to respond.
If your thinning is progressive, a dermatologist can confirm the cause and discuss options with stronger evidence behind them. Some clinics pair medical treatment with procedures such as scalp microneedling, and there is clinic evidence on microneedling alongside minoxidil over 12 to 16 weeks that is worth reading before you decide.
Our honest summary: homemade rosemary oil is a low-cost scalp ritual that may support a hair routine. It is not a replacement for medical treatment when hair loss is advancing.
How to tell whether it is working
Because results take months, memory is a bad judge. Hair looks different with lighting, length and styling, and a good-hair-day photo proves nothing.
What helps:
- Take photos of the same parting and crown area in the same light, once a month.
- Note how many hairs you see in the shower drain or on your brush, while keeping in mind that some shedding is normal.
- Give any routine at least three to six months before drawing a conclusion.
- Change one thing at a time. If you start a new shampoo and rosemary oil on the same day, you cannot know which did what.
Our perspective
We built MyHair around a simple observation: people who search for rosemary oil are usually not looking for a recipe. They are worried about their hair and want to know if something simple can help. The recipe is the easy part. The hard part is knowing whether your hair is actually changing.
So we tell readers the same thing every time. Try a gentle, properly diluted oil if you like the ritual. Protect your scalp by patch testing. Do not treat a kitchen remedy as a verdict on your hair. And measure, instead of guessing, because hair changes slowly and unevenly.
We also think recommendations should be personal. A person with an oily scalp and early thinning at the temples needs different advice from someone with dry, breakage-prone hair. That is why our app focuses on scanning, tracking change over time and tailoring suggestions, rather than handing out one-size-fits-all lists. If you are comparing oils, our roundup of hair oils for thinning hair shows how we weigh the evidence.
— Cyriac
Track your results with MyHair
If you are going to spend three to six months on a scalp routine, it helps to see what is happening. With the MyHair app you can scan your hair, follow changes over time and get product suggestions based on your own results. There is a free plan to start with, and the monthly plan is $9.99 per month if you want the advanced analysis.
If your hair loss looks like it is progressing, you can also browse hair clinics and hair restoration doctors in our directory.
Mistakes that ruin a homemade batch
A few errors come up again and again in comments under DIY recipes:
- Using fresh sprigs. This is the biggest risk, for the moisture reasons covered above.
- Overheating. Hot oil can degrade the plant material and can burn your scalp. Keep the heat low and let the oil cool fully before use.
- Storing at room temperature for weeks. Refrigerate and use quickly.
- Adding extra drops. More essential oil means more irritation risk, not faster growth.
- Skipping the patch test. A reaction on your whole scalp is much worse than a reaction on one small spot.
- Leaving it in for days. Wash it out.
FAQ
How do you make rosemary oil for hair?
The safest quick method is mixing about 6 drops of rosemary essential oil into 2 tablespoons of carrier oil, which is roughly a 1% dilution. For an infusion, warm crisp, dried rosemary in olive oil on low heat for 30 to 60 minutes, then strain. Keep the infusion in the refrigerator and use it within a few days.
What is the best carrier oil for rosemary oil?
Cleveland Clinic names coconut oil and jojoba oil as options for diluting rosemary oil. We lean toward jojoba for fine or oily hair because it is light, and olive oil if you are making an infusion. Choose whichever your scalp tolerates and that washes out well for you.
Can I leave homemade rosemary oil in my hair?
Leave it on for at least a few hours, or overnight, then shampoo it out. We would not leave a homemade oil on for days, since it contains no preservatives and can build up on the scalp.
Is rosemary oil proven to regrow hair?
Not conclusively. A small 2015 trial found promising results compared with 2% minoxidil, but it had no placebo group and has not been widely replicated. If you are losing hair steadily, see a dermatologist rather than relying on a home remedy.
Sources
- Cleveland Clinic: How to use rosemary oil for hair growth
- Cleveland Clinic: Using essential oils to treat coughs
- Washington State University Extension: Making garlic- and herb-infused oils at home
- University of Georgia Extension: Home food preservation
- PubMed: Rosemary oil vs minoxidil 2% for androgenetic alopecia, 2015 trial
- Clinic evidence on microneedling and minoxidil
- Dilution guidance for rosemary essential oil