“Sebaceous filaments are naturally occurring tiny collections of sebum which are a part of the pore construction,” says board-certified dermatologist Hadley King, M.D. “They line the within of the pores and help within the circulation of sebum alongside the liner into the pores and skin to assist moisturize it.” They’re made up of triglycerides, wax esters, and squalene, King provides—all of that are obligatory for a wholesome glow. 

For essentially the most half, sebaceous filaments stay invisible lives, serving to to circulation sebum beneath the pores and skin’s floor. It’s whenever you do discover some specks (normally a yellow-ish, off-white, and even grey coloration) that it turns into a problem: Ever pull your pores and skin taut to seek out small, white pinpoints dotting the realm? This implies your pores have clogged up with an excessive amount of sebum, useless pores and skin, and micro organism. “These are annoying cosmetically,” says board-certified dermatologist Jeanine Downie, M.D., as you possibly can’t actually really feel them beneath your fingers. 

They’re sometimes most seen alongside your T-zone, Downie mentions, as that’s the place individuals are likely to accrue essentially the most oil. Typically vellus hairs may even turn into trapped throughout the pore, leading to a situation known as trichostasis spinulosa. (For what it’s price: Each trichostasis spinulosa and sebaceous filaments are sometimes confused for blackheads.)