Pure mustard oil is not permitted for use as a vegetable oil in many countries around the world, including the United States, Canada, and Europe (1).

This is because it contains a compound called erucic acid, which is a fatty acid that can have serious adverse effects on heart health (30).

On the other hand, mustard essential oil is extracted from mustard seeds via a steam distillation process, and the Food and Drug Administration (FDA) has deemed it generally recognized as safe (GRAS) as a flavoring agent (1).

Although the two are considered different types of oil, they are both extracted from mustard seeds and share many of the same beneficial compounds.

Both can also be diluted with a carrier oil, applied topically, and used as a massage oil or mixed into homemade skin serums and scalp treatments.

Be sure to perform a patch test by applying a small amount to your skin and wait at least 24 hours to check for any redness or irritation.

There’s currently no recommended dosage for mustard oil, and research on the effects of its topical application among humans is lacking.

Therefore, for topical use, it’s best to start with a small amount of around 1 tablespoon (14 mL) and increase slowly to assess your tolerance.

SUMMARY

In many countries, mustard oil is banned for use in cooking and can only be applied topically. However, mustard essential oil is safe for culinary (as a flavoring) and topical use. Be sure to do a patch test and use a small amount to assess your tolerance.

The bottom line

Pure mustard oil is a type of oil that’s made by pressing the seeds of the mustard plant.

Because pure mustard oil contains harmful compounds like erucic acid, mustard essential oil is considered a better choice as a flavoring agent.

Pure mustard oil and mustard essential oil may help reduce inflammation and pain, slow cancer cell growth, block microbial growth, and enhance hair and skin health.

Both can also be diluted with a carrier oil and applied topically in massage oils, face masks, and hair treatments.