To dilute peppermint oil, mix it with a carrier oil at a ratio of 1% to 3%, depending on where and how you plan to use it. For most purposes, a 2% dilution is the standard starting point, which works out to about 12 drops of peppermint oil per ounce (2 tablespoons) of carrier oil. The math is straightforward once you know the basics, and getting it right matters because undiluted peppermint oil can burn or irritate skin.
Dilution Ratios by Use
The right concentration depends on what you’re using the oil for and where it’s going on your body. Skin on the face is thinner and more reactive than skin on the back or legs, so facial applications call for a weaker mix. These are the standard ranges:
- Face (masks, facial oils): 1% or less, roughly 6 drops per ounce of carrier oil
- Body massage and leave-on products: 2%, roughly 12 drops per ounce
- Rinse-off products (body wash, bath blends): 3%, roughly 18 drops per ounce
Topical dilutions above 5% are not recommended. Even at 3%, peppermint oil produces a noticeable cooling and tingling sensation. If you’ve never used it before, start at 1% on a small patch of skin and wait 24 hours to check for redness or irritation before applying it more broadly.
How to Measure Drops Accurately
A standard dropper produces about 30 drops per milliliter, and one teaspoon holds roughly 5 milliliters. That gives you a simple conversion: one teaspoon of carrier oil holds about 150 drops total. To hit a 2% dilution in one teaspoon of carrier oil, you’d add about 3 drops of peppermint oil. For a full tablespoon (three teaspoons), that’s about 9 drops.
Drop size varies slightly depending on the thickness of the oil and the dropper opening, but the 30-drops-per-milliliter standard, used by the Tisserand Institute, is reliable enough for home blending. If you’re mixing larger batches or want more precision, a small kitchen scale that reads in grams works well since 30 drops of essential oil weigh close to 1 gram.
Choosing a Carrier Oil
The carrier oil you pick affects how the blend feels on your skin and how quickly it absorbs. Three options pair especially well with peppermint:
- Almond oil: Absorbs easily and has a mild, neutral scent that doesn’t compete with peppermint’s cooling aroma. A good all-purpose choice for massage and body application.
- Grapeseed oil: Lightweight and fast-absorbing, so it doesn’t leave a greasy film. Works well in massage blends or when you want the oil to sink in quickly.
- Avocado oil: Heavier and more moisturizing, which makes it better for dry skin or targeted application on rough patches. It penetrates deeply and provides longer-lasting hydration.
Fractionated coconut oil (the liquid kind that stays clear at room temperature) and jojoba oil are also popular. Jojoba is technically a wax, which makes it exceptionally stable. It resists going rancid far longer than most plant oils.
Diluting for Scalp and Hair Use
Peppermint oil is often used on the scalp to stimulate blood flow and support hair growth. A study published in Toxicological Research tested a 3% peppermint oil solution diluted in jojoba oil, applied once daily to the skin, and found it promoted significant hair growth in mice over four weeks, outperforming both saline and jojoba oil alone.
To make a similar blend at home, add about 18 drops of peppermint oil to one ounce of jojoba oil. Apply a small amount directly to the scalp with your fingertips, massaging it in for a few minutes. The cooling sensation is normal. If it feels like burning rather than tingling, wash it out and reduce the concentration. Many people apply this a few times per week rather than daily, which is a reasonable approach for a home routine.
Safety Around Children and Pets
Peppermint oil contains a high concentration of menthol, which poses specific risks for young children. Johns Hopkins Medicine advises against using peppermint oil on children under 30 months old because menthol can increase the risk of seizures in that age group. For older children, peppermint can help with headaches and nausea, but it should still be used at a 1% dilution or less and kept away from the face, especially near the nose and mouth.
Pets are more vulnerable than most people realize. Cats are particularly sensitive because they lack certain liver enzymes needed to break down compounds in essential oils. Concentrated peppermint oil should never be applied directly to any pet. Even diffusing it carries risk: microdroplets can settle on fur or feathers and then be ingested during grooming. Symptoms of essential oil exposure in animals include vomiting, drooling, lethargy, tremors, and difficulty breathing. According to the Merck Veterinary Manual, severe cases can lead to liver or kidney failure. If you diffuse peppermint oil at home, keep pets out of the room, run the diffuser for less than 30 minutes, and ventilate the space afterward.
Storing Your Diluted Blend
Once you’ve mixed peppermint oil into a carrier oil, the shelf life of your blend depends mostly on the carrier. Peppermint essential oil itself stays potent for about three years when stored properly. But carrier oils can go rancid, and an oxidized carrier oil won’t just smell off. It can irritate skin.
Jojoba is the most stable carrier and resists rancidity well, especially if stored below 50°F. Grapeseed and hazelnut oils are less stable and need to be kept away from heat and sunlight. Avocado oil falls in the middle, storing well as long as you keep it cool. For any blend, use a dark glass bottle with a tight-fitting lid and store it in a cool place. The refrigerator is ideal for extending shelf life. If the oil starts to smell musty, sharp, or “off” compared to when you first mixed it, discard it and make a fresh batch.