The new oil boom

Stroll through any department store, vitamin shop or farmers market and you’re bound to find little vials filled with strong-smelling oil. These pungent elixirs are extracted from fragrant botanicals, like lavender, citrus, peppermint and cloves. “If you think about when you squeeze a lemon, the very strong citrus smell that you get is the essential oil being released from the skin,” said Wendy Weber, Ph.D., N.D., chief of the clinical research branch at the National Center for Complementary and Integrative Health at the National Institutes of Health.

Sales revenue from these potent plant extracts in the United States increased by nearly 40 percent from 2014 to 2018. By 2025, they’re projected to reach more than $5 billion in total sales, according to market research firm Grand View Research.

But they’re not just being sold in shops and online. Sheie said that she’s increasingly had to politely sidestep sales pitches from people in her social circles who are selling the oils for two of the largest essential oil companies, doTerra and Young Living. These manufacturers use multilevel-marketing strategies, where the people who sell their products profit from their own sales as well as those of others they recruit (think Avon or Herbalife). “I most often run into it at church and on social media, especially in my mom groups,” she said.

But can they improve your health?

Some sellers — along with particular social media posts and websites that expound the oils’ benefits — attest with a kind of evangelical zeal that certain essential oils can help treat a range of ailments, from attention deficit disorder and depression to Alzheimer’s disease, cancer, skin abrasions, infections, teething pain and more. Companies commonly market essential oils to parents for their purported ability to boost kids’ immune systems and to improve focus, mood and sleep.

But the bulk of the research done on essential oils has been performed in petri dishes and on rodents. “There are few human studies, and they are mostly small and of low quality,” Dr. Smith said.

And of the research that has been done on humans, said Dr. Smith, the bulk of the studies on essential oils’ effectiveness and safety has been performed on adults. A few studies in children suggest that inhaling lavender oil can have a calming effect; that topical applications of tea tree oil may be useful against acne, lice and warts; and that peppermint oil capsules may help with irritable bowel syndrome and abdominal pain.

However, there’s no evidence to support essential oils’ more common uses, such as for treating “fever, cough, congestion, allergies, teething symptoms and (the one that makes me the most frustrated) behavior problems,” Dr. Smith wrote in a column for Cook Children’s Health Care System in 2015.