Methyl salicylate is a colourless to pale-yellow liquid with a strong, cooling, wintergreen-like aroma, used mainly as a fragrance and warming agent in pain-relief balms, cosmetics and personal-care formulations. It is the same compound naturally found in wintergreen and sweet birch, which is why it is often sold as "wintergreen oil". At Azlok it is offered as a 99% pure technical-grade liquid (CAS 119-36-8), made by esterifying salicylic acid with methanol.
What is methyl salicylate?
Chemically, methyl salicylate is methyl 2-hydroxybenzoate, with the formula C8H8O3 and a molecular weight of about 152.15 g/mol. It occurs naturally in plants like the wintergreen and sweet birch tree, but most commercial material is produced through a controlled reaction between salicylic acid and methanol. The result is a clear liquid with a persistent, characteristic scent that is instantly recognisable from many muscle rubs and antiseptic products.
Common uses
This ingredient shows up in a surprising number of everyday products. Here are the main ways formulators use it:
- Pain-relief creams and balms: It creates a warming, soothing sensation on the skin, which is why it is a core ingredient in muscle and joint rubs, sports gels and back-pain lotions.
- Fragrance: Its clean, minty-medicinal aroma is used to scent creams, lotions, ointments and some oral-care products.
- Cosmetic formulations: It is added in small amounts to skincare and haircare products as a fragrance component, and it can contribute mild preservative-type activity.
- Aromatic blends: Candle and soap makers sometimes use it for its distinctive wintergreen note.
How to use it in formulations
Methyl salicylate is potent, so a little goes a long way. It is miscible with ethanol (95%), chloroform, and fixed and volatile oils, but only very slightly soluble in cold water. Because of this, blend it into the oil phase of your formulation or dissolve it in alcohol before combining.
- Always work to a written recipe with defined percentages rather than eyeballing.
- Keep the level low in leave-on products — most topical balms use it well within regulatory limits, so follow published cosmetic guidelines for your region.
- Add it towards the end of a warm blend, since the strong aroma is volatile.
- Make a small test batch first and check the scent strength and skin feel before scaling up.
Safety notes you should not skip
Methyl salicylate is powerful and must be handled with respect. Please treat these points as essential, not optional:
- Do not ingest. Swallowing even small quantities of concentrated methyl salicylate is dangerous, especially for children. Keep it locked away and clearly labelled.
- Never apply neat to skin. Always dilute it properly in a finished formulation and follow safe-use levels.
- Patch-test any new formulation on a small area before regular use, as it can irritate sensitive skin.
- Avoid use with heat or occlusive wraps over treated areas, which can increase absorption.
- Handle with ventilation. The aroma is strong and persistent; work in an airy space and avoid prolonged inhalation.
- The flash point is around 96 °C, so keep it away from open flames and store sensibly. This is a technical-grade material intended for formulation, not for direct consumption.
Buying and storage tips
Azlok stocks methyl salicylate in packs from 100 g up to 25 kg, so hobbyists and small manufacturers can both find a suitable size. Look for the purity (99%) and ask for the COA and MSDS when buying in bulk. Store the liquid in a tightly closed, well-labelled container away from light, heat and children, ideally in a cool, dry place. Kept properly, it has a shelf life of around 24 months. Because the odour is strong and clings to surfaces, use dedicated measuring tools for it.
FAQ
Is methyl salicylate the same as wintergreen oil?
Effectively yes in common usage. Methyl salicylate is the main aromatic compound in natural wintergreen oil, and the terms are often used interchangeably. The Azlok product is a synthesised, high-purity version made from salicylic acid and methanol.
Can I apply methyl salicylate directly to my skin?
No. It should never be used undiluted. Incorporate it into a properly formulated cream, balm or lotion at safe levels, and always patch-test the finished product first.
What does methyl salicylate do in pain-relief balms?
It produces a warming, soothing sensation on the skin and is valued for its counter-irritant and comforting effect, which is why it features in many muscle and joint rubs.
How should I store it?
Keep it in a tightly sealed container, away from heat, sunlight, open flames and children. A cool, dry cupboard is ideal, and the product stays usable for about 24 months.
Is it safe to swallow?
No. Methyl salicylate is for external, formulation use only and is toxic if ingested, particularly by children. Store it securely and never take it internally.