Can Slugging Make Your Hair Grow?
Experts tell us how petroleum jelly can make—or break—your gorgeous hair
Fine hair is usually associated with oily hair, but mine tends toward dry: It can be brittle, dull, and prone to breakage, even before I started regularly highlighting it last year. And though I have a fair amount of it, its thin, delicate texture has long left me envious of my friends with a full head of thick, luscious waves. So I was intrigued when I heard that many Consumer Reports readers were commenting on a previous article I’d written about face slugging, in which people with dry skin apply Vaseline or other oils to the skin. The commenters were extolling the incredible hair growth properties of hair slugging. Many people believe putting Vaseline in the scalp and hair can encourage the hair to grow and moisturize the hair shaft, transforming lackluster curls into enviable ones. Hair “slugging” is far from a new trend, says Chesahna Kindred, a dermatologist and the founder of Kindred Hair & Skin Center in Columbia, Md. Generations of Black Americans “called this ‘greasing the scalp’ or ‘oiling the hair.’” This is thought to soothe a dry scalp, calm irritation, and promote hair growth.
Why Slugging Won’t Promote Hair Growth
“Petroleum jelly does not promote hair growth,” says Kindred, adding that it can cause seborrheic dermatitis (a form of skin irritation that includes dandruff), in which the skin becomes red, itchy, and peeling. On the face, petroleum jelly can lock in moisture and make dry skin hydrated and dewy, but Kindred says that on the scalp, it can create a moist environment in which the yeast that causes seborrheic dermatitis thrives. “In my experience, if someone is suffering from dandruff, the petroleum jelly will camouflage the scaling or flaking while worsening the condition within a couple of daily applications,” she says.
Petroleum jelly “may be good for dry skin on the face, however I do not recommend it for use on the scalp as it can block up hair follicles,” says David E. Bank, a dermatologist and the founder of the Center for Dermatology, Cosmetic & Laser Surgery in Westchester County, N.Y.
Vaseline isn’t the only thing that can do this. Sweat, sebum (a waxy, oily substance naturally produced by glands in the skin), and product buildup (such as dry shampoo or hairspray) can all accumulate on the scalp. The simplest and most economical way to treat scalp buildup is a salicylic acid shampoo, says Ranella Hirsch, a dermatologist based in Cambridge, Mass. “The key is allowing it to sit on the scalp for a while—5 minutes,” she says. “People see the word ‘shampoo’ on the label and rinse it out quickly, when they should really use it as a scalp treatment.”
Another option is a clarifying shampoo, for use every 15 days to mitigate buildup.
“The main concern about using Vaseline on the scalp would be folliculitis,” says Christina Boull, an assistant professor of dermatology at the University of Minnesota Medical School in Minneapolis. “If someone is prone to this condition, which is a yeast or bacterial infection of the hair follicles, use of Vaseline could make this worse by trapping infection.” Severe cases of folliculitis can cause permanent hair loss.
Despite being a popular beauty tip on TikTok, petroleum jelly is equally useless for hair growth on other parts of the body, such as the eyelashes and eyebrows. “Different hair areas, such as eyebrow, eyelash, facial, and scalp, do not respond to ‘hair slugging’ to promote any new hair growth,” Bank says.
Better Solutions for Faster-Growing Hair
“Ideally, step one is to see a doctor who can examine you and check labs,” Hirsch says. “A number of causes of hair loss can be related to an underlying medical cause,” such as thyroid dysfunction, recent illness, or pregnancy.
Bank says Rogaine, which is available over the counter, and the prescription-only medication Propecia are the best solutions for encouraging head hair growth. Hirsch agrees, adding that all genders can use Rogaine, with the exception of people who are pregnant.
“Pro tip: Rogaine is sold as a woman’s version and a man’s, with (natch) a solid 40 percent-plus pink tax surcharge for the women’s version,” Hirsch says. “They are identical—save your money.” Biotin and most supplements are popular, but largely ineffective, treatments for hair loss, Hirsch adds.
Slug Your Hair, Not Your Scalp
Slugging “does improve dry hair,” Kindred says.
Similar to face slugging, this works by sealing moisture and oils into the hair shaft. Dry hair is more brittle, and can break more easily than healthy, hydrated hair. And hair that’s breaking at the end obviously won’t grow as long as hair that isn’t, even if it’s not coming out of your scalp at an accelerated rate.
Apply Vaseline over leave-in conditioner for maximum hydration benefits, Kindred says. “Leave-in conditioners moisturize the hair and fill in holes in the hair shaft, making the hair stronger and more resilient. Vaseline or petroleum jelly coats the hair, preventing dryness,” she says. This can weigh down the hair, she adds, which may or may not be desirable, depending on the style.