Homemade, natural sunscreens may leave you risking a burn

Homemade sunscreens on Pinterest may look pretty and smell even prettier, but most of them won't shield you from sunburn or skin cancer, new research shows.

"Ninety-five per cent of the pins really positively portrayed the effectiveness of homemade sunscreens, yet about 65 per centwere recommending recipes that offered insufficient ultraviolet radiation protection," Dr. Julie Merten of the University of North Florida in Jacksonville, the lead author of the new study, told Reuters Health by phone.

Ultraviolet (UV) radiation exposure from the sun and from indoor tanning is by far the leading cause of skin cancer, which will affect 20 per centof Americans at some point in their lives, Merten and her team note in a report released by the journal Health Communication. Sunscreen helps prevent sunburn, and regular use reduces skin cancer risk.

The U.S. Food and Drug Administration has tested and approved 17 active sunscreen ingredients, but concerns ranging from coral reef damage to hormone disruption have led many people to search for alternatives.Canadians are advised to choose a sunscreen that is water resistant with an SPF of at least 30.

Merten and her colleagues analyzed a sample of 189 pins mentioning homemade or natural sunscreen. Coconut oil was the most common ingredient. Many recipes also featured lavender oil, raspberry oil, shea butter or beeswax. Sixty-three of the pins claimed a specific sun protection factor (SPF) number, ranging from 2 to 50.

"This is concerning, because the ingredients recommended in homemade sunscreen pins offer minimal scientifically proven broad-spectrum protection from UV radiation yet are widely shared and promoted as safe alternatives to commercial sunscreens on Pinterest," Merten said.

"Homemade sunscreen products are risky because they are not regulated or tested for efficacy like commercial sunscreens. When you make it yourself, you don't know if it's safe or effective," she added. "With rising skin cancer rates, the use of effective broadband sunscreen is critical to protect the skin from UV radiation and reduce incidence of skin cancer."

"As public health professionals, [we advise people to use]a commercial sunscreen, and if you're concerned about the chemical piece go for a mineral sunscreen such as zinc oxide," she said.

Dr. David Leffell, a professor of dermatology and surgery at Yale School of Medicine in New Haven, Conn., reviewed the study for Reuters Health.

"I would not encourage anyone to make their own sunscreen," he said by phone. "Sunscreen formulation is actually quite complex. Despite concerns about various ingredients that come up, they are proven to be effective."

"I think it's part of an overall trend in health care of self-diagnosis and self-treatment," Leffell added. "It's not going to change, but I would think that after someone has a bad sunburn after using their homemade beeswax formulation they will get smarter."

The American Academy of Dermatology recommends using a water-resistant sunscreen with an SPF of at least 30 that is broad spectrum, meaning it protects against both UVA and UVB.