One of my favourite skin-care ingredients is hyaluronic acid (which is so much easier to type than to pronounce). I know I'm not alone in this. Because my skin is dry, I always look for HA in my skin serum. Hyaluronic acid's claim to fame is that it's a humectant (used to reduce moisture loss) that can bind up to 1,000 times its weight in water, which has always sounded like a positive to me.
But recently, at a facial, as I was confidently reciting my HA-heavy product routine to my aesthetician while she examined my pores under a microscope when she said: "I think you're actually using too much hyaluronic acid." My palms started to sweat from too much coffee prior to my appointment, the heated blanket underneath me, and a feeling of embarrassment for being low-key skin-care shamed. "I didn't know that was possible," I stuttered.
Does hyaluronic acid have side effects?
The most common misconception about hyaluronic acid is that HA equals hydration. According to Dr. Hadley King, a dermatologist, hyaluronic acid temporarily hydrates the skin, but it's not a long-term cure all. Also, there are some instances where HA can actually cause dehydration, which happened to me.
My aesthetician, a registered nurse at Skinceuticals SkinLab in NYC, explained that when hyaluronic acid is applied liberally to dry or dehydrated skin — me, in NYC with no humidifier, regrettably — it pulls moisture from the from the skin's internal, structural layers. "If your skin is dehydrated to begin with, and the air around you is dry, then the product can actually suck water from deeper in the skin," Ava Shamban, M.D., a Beverly Hills-based dermatologist explains to Refinery29. While I had good intentions for a quick-hit of hydration with HA, I was missing some key guidance: add water.
How to apply hyaluronic acid
According to skin experts, hyaluronic-acid serum should be applied to damp skin to work most effectively. That way, the HA has water to bind to, and doesn't have to pull it from within. "You need to apply it to moist skin — which is why you should mist first and then apply a hyaluronic-acid treatment afterwards," Allies of Skin founder Nicolas Travis tells Refinery29. "Once hyaluronic acid comes into contact with water, it knows what it's doing and your skin will end up supremely hydrated and plumped." Sometimes, I'll cleanse my face, pat it gently with a towel so it's not dripping wet, and then immediately apply my HA serum. That way, I cut out the need for a face-mist step. But do what works for you.
The other important use guidance: I needed a barrier moisturiser over top. "If not used in conjunction with emollients and occlusives, particularly in dry environments, hyaluronic acid can lead to loss of moisture from the skin into the air," explains Dr. King. "It needs to be used along with the other components in order to retain the water content." Emollients include squalane, fatty acids, and ceramides. Occlusives include petrolatum (i.e. petroleum jelly). Basically, to avoid transepidermal water loss, I should have been slugging.
Is it okay to use hyaluronic acid every day?
Dr. King says, it's great to use HA both morning and night, so long as it's not just straight HA by itself in a high concentration. It should always be combined with water, and an emollient or occlusive moisturiser if you live in a dry environment. "Because it's a powerful humectant, hyaluronic acid is a great topical hydrator safe for daily use," Dr. King explains. "As long as either the environment is humid, or you combine it with emollients and occlusives to lock in the hydration so it doesn't pull water out of the skin."