Unlike the current dating climate, labels are everything when it comes to skin care. Brands want you to know that their products are clean, are natural, or contain buzzy ingredients. They're also sure to let you know when a product has been clinically tested. But what does that mean, exactly?

Simply put, skincare brands opt into clinical testing because they want to prove that the products work for a specific condition. "The skincare market is extremely competitive, so research-proven products tend to get noticed by customers," said Dr. Dhaval Bhanusali [1], a dermatologist in NYC.

Clinical trials often consist of companies asking a sample of people to use the product for a certain period of time, documenting the effects through before-and-after photos. The brand might also follow a control group of people who are not using the product and compare the results with the people who are. "In general, company employees are the ones who determine whether the endpoints are being met or not," said Dr. Papri Sarkar [2], a dermatologist in Boston.

Clinicals are often used on individual products that are made to be sold together as one regimen. "Brands want to be able to claim that all the steps work together and that you get better results if you use them in tandem," Dr. Sarkar said. "While that is one way to go about it, testing the products as part of a routine can make it difficult for consumers to tease out which product in particular helps their individual concern."

Dr. Bhansuli noted that clinicals are required for any product that claims to contain SPF. "If you are in the market for SPF or sunscreen, it's very important to only use products that have done extensive testing."

There are a few good reasons for brands to not subject their products to clinicals, and that doesn't necessarily mean you shouldn't buy a serum that hasn't undergone such testing. For one, clinicals are expensive and take time to set up and conduct. "If a brand already has a cult or loyal following, sometimes its founders will opt out of clinicals and just use anecdotal testimonials," Dr. Sarkar said.

When Kerry Benjamin founded StackedSkincare [3], she made the conscious decision to forego clinicals. She had self-funded her business, which meant that unlike larger brands, she didn't have an unlimited budget. "I decided that Stacked would spend its resources on getting high-quality ingredients, which would ensure their efficacy," she said. She also sources her products from raw material suppliers that conduct their own clinical trials before sending them over.

In the end, most dermatologists agree: it's your own money, so spend it the way you damn please. That said, if you're unsure to pick an Instagra-famous face mask or one that's been clinically tested, Dr. Bhansuli said many dermatologists would prefer the latter. "I would generally recommend to pick products that are backed by science," he said. "If a brand relies more on marketing than testing, there could be an issue with the product."