Photo: NikiLitov/Getty Images/iStockphoto

We’re not supposed to have a favorite child, but everyone does, right? I have no human spawn but bear a motherly affection for my skin-care children nestled in their protective glass bottles. (No, they don’t have a skin-care fridge — I want them to grow up scrappy, not spoiled.)

Gazing at their squishy little dropper heads, I have to admit a truth, even at the risk of their reading this on the internet when they’re older: I like some of them better than others. My golden babies are the hyaluronic acid (HA) serums and moisturizers that have kept me smooth through this past New York winter, plumping my skin and giving it the rebound of a freshly inflated bouncy castle.

However, I’ve discovered recently that one can love hyaluronic acid a little too much. HA is a naturally occurring substance found in our skin. It holds 1,000 times its weight in water, keeping skin plump and supple. In skin care, it’s used — and raved about — for its humectant properties, which help to draw and hold moisture, resulting in firmer-looking, hydrated skin. It’s not an exfoliating kind of acid, but it turns out you can still overdo it.

I’d been using HA to hydrate my cheeks, which are red and irritated — one of my longest-standing skin-care issues. Lately, I’d been cocktailing HA with ceramides, oils, and panthenol, all of which repair a compromised skin barrier. I’d cut out irritating actives like retinol, acids, and vitamin C, as well as unnecessary additives like fragrance. I’d toiled for months and made a little progress, but this zone was always on the verge of spontaneous combustion.

I was about to give up, figuring the cause was internal, when I saw a post on licensed aesthetician and cosmetic formulator Mary Schook’s Instagram. A “before” image of a client’s irritated skin was contrasted with a picture after she’d stopped her HA serum, showing a dramatic difference in inflammation and redness. It seemed crazy, but since summer had finally sprung, I figured it wouldn’t hurt to cut out the HA-heavy skin-care steps that had been cocooning my visage all winter long. I scanned the ingredient lists of all my products for hyaluronic acid and sodium hyaluronate — there were a lot! — and banished them for a week, per Schook’s instructions.

Of course, I had separation anxiety — I woke up with the opposite of thicc skin (dare I call it thinn?) and a web of fine lines under the eyes. I caved a couple of times and reached for the HA, but for the most part, I held firm. After five days, my skin was more even-toned, the redness had reduced dramatically, and some inflammatory spots had cooled off. I felt confused and betrayed. Had hyaluronic acid really failed me in this epic way?

HA’s immense capacity to hold water can have a Mr. Hyde side. It needs moisture to work, so when applied to skin in dry conditions where humidity is low, it will pull moisture from wherever it can; that’s just the nature of the beast. If there’s no humidity to be obtained from the air, it draws moisture from the deeper layers of skin and brings it to the surface of the epidermis, whence it evaporates, leaving skin drier than it was. That’s why beauty pros suggest following these best practices while using HA: Apply it to damp skin, then top it off with a moisturizer or oil to seal it in.

I had been going through all these motions religiously, so I knew the problem wasn’t my practice. So I visited Schook, who said she’s been seeing a lot of clients with similar HA sensitivities. “You won’t notice initially; it’s usually a late-onset situation. Your skin gets red and pissed off, and the barrier is broken with raised pimple-like spots.” That sounded a bit like my current condition; my sensitive skin combined with a compromised barrier couldn’t deal with all the HA I was throwing at it.

Schook was doubtful my inflammation was caused by internal factors like digestion or kidney-related issues, as that diagnosis didn’t vibe with my South Asian ethnicity and my Fitzpatrick skin type of IV. (The Fitzpatrick scale classifies skin into six groups according to the amount of pigment it contains and how it reacts to sun exposure.) She tested a few ingredients on my skin, determined it was reactive and compromised, and suggested I keep things kosher with a basic moisturizer that used glycerin as a humectant instead of HA.

After I spoke to Schook, some Sherlocking turned up research that suggests that what separates the benign, do-gooder HA from its inflammatory cousin might be its molecular size. Some years ago, scientists figured out how to break down larger HA molecules that sat on top of the skin into smaller pieces that penetrated better, thus increasing hydration in the deeper layers of skin. However, the resulting low-molecular-weight HA has been shown to be inflammatory, in contrast to the higher-molecular-weight version, which is the opposite.

“Hyaluronic acid of low molecular weight is the remnants or waste product, and not part of the original construct of HA,” says Dr. Harold Lancer, a board-certified dermatologist. He reminds us that HA is part of the human body to begin with, so there is no reason for it to be inflammatory. “If you take it from its natural, vibrant form and turn it into debris or waste, it’s going to be inflammatory.”

The take-home is not that all hyaluronic-acid types are bad for your skin, says Dr. Shereene Idriss, a board-certified dermatologist at Union Square Laser Dermatology. “High-molecular-weight HA has been shown to have an anti-inflammatory effect. On the other hand, studies are correlating topical application of low-molecular-weight HA (the type needed to penetrate the surface of your skin barrier) with inflammatory reactions.” Dr. Idriss has observed this cause and effect in some (but not all) of her patients. “Once they stopped topically applying the low-weight HA, their inflammation resolved.”

If you suspect you might be having a reaction to HA and are wondering how to scan ingredient lists for the low-molecular-weight version, here’s a clue: Brands will typically declare it on the packaging, because the high cost of low-molecular-weight HA makes it a point of advertising. It’s in products from brands like the Ordinary that are known for providing top-grade ingredients at a lower cost, as well as in luxe skin-care products like those from Dr. Barbara Sturm.

“The lower-molecular-weight HA raw material is always priced more expensively, and certain brands will use this as a key claim to position [themselves] in the prestige category,” says Victoria Fu, a skin-care chemist and co-founder of Chemist Confessions, a popular beauty Instagram and blog. Brands would be shouting from the rooftops if lower-molecular-weight HA was in their formulas, says Gloria Lu, also a Chemist Confessions co-founder. A quick scan of my daily products proved them right: Two out of five contained low- and very low-molecular-weight HA, and that was clearly highlighted on either the product packaging or website.

Fu agrees that lower-molecular-weight HA may be more problematic for people prone to an HA sensitivity, but by and large, she considers HA to be a pretty vanilla ingredient. “Often, rather than a problem with HA, it’s a confusion in usage. If you don’t use something like a cream or oil to seal it in, it can cause dryness.”

If you haven’t observed any reactions to HA, here’s some intel from the pros to safely use it. While HA is great at drawing moisture into skin, it needs some help keeping it there. Typically, products containing HA are formulated with occlusive or emollient ingredients that will help lock it in. You’re golden if the ingredient list of your HA product includes an occlusive ingredient; look for olive, avocado, or castor oils, shea or cocoa butter, or allantoin and lecithin. However, if your product of choice contains not much more than HA, you’re going to need to bring in additional reinforcements. “Use a moisturizer to increase the benefit of the HA, seal it and enhance the retention of fluid,” says Dr. Lancer. Topping your HA serum, mist, or toner with an oil or moisturizer will seal the deal. And to turbo-charge the potency of HA, start your skin-care routine with a damp face so it has a reserve of moisture to pull from.

Pros agree that there’s absolutely no reason for younger people to be using HA, because that’s when the skin is pumping out enough of its own. “There’s minimum evidence it works in younger people because their HA receptors are already working. It’s more for people who are losing their skin’s natural reserves,” says aesthetician Rhea Souhleris Grous, founder of La Suite Skin Spa in Greenwich, Connecticut, and New York. So kids, please drink from your own fountain of youth and leave the man-made stuff for the rest of us.

Dosage is also a factor — with HA, a little goes a long way. Look for concentrations between 0.2 percent and 0.5 percent; even 1 percent is quite high. As with most active ingredients, do a patch test and start small, building up to higher percentages. Fu and Lu also told me it was wasteful to have HA in multiple skin-care products in the same routine (ashamed emoji). Apparently, one HA-containing product is plenty.

If you suspect HA is freaking your skin out, you might be interested in my plan of action: I said goodbye to my hyaluronic-acid excess and have been extending my self-inflicted drought to see how my skin responded, keeping all other products and factors the same. It’s easy to see that my skin has just been happier after this HA breakup. The inflammation has subsided and my tone is more even, so I’m going to be HA-free for the near future. I might try reintroducing it after a few months, and only time will tell if my prodigal offspring can redeem themselves. Who knows, a skin-care fridge might be their homecoming reward.