MIAMI — The makeup industry is trying to convince women that looking good on the outside starts from within — but it's unclear whether the products they're trying to hawk are safe and effective.

Big-name beauty companies and retailers including Sephora and Urban Outfitters are rolling out everything pills and drinkable liquids loaded with exotic herbs, vitamins, seeds, berries and substances such as collagen. The products promise to do things such as firm up skin and improve its natural glow.

The trend is picking up steam. Although a small portion of the $16 billion beauty products market, sales of beauty supplements targeting the face have more than tripled from less than $1 million in 2013 to over $4 million in 2015, according to market research firm the NPD Group.

But unlike the instant glam provided by a swipe of blush or lipstick, pills and other so-called “nutraceuticals” add a layer of questions about safety and effectiveness as some consumers may see ingesting something in the name of looking lovely a lot differently than simply rubbing something into the skin. And similar efforts have tanked in the past: Industry titans such as Oil of Olay peddled vitamins promising glowing skin and hair more than a decade ago to no avail.

Today, companies are being buoyed by celebrities who swear by these ingestible beauty products. In January, actress Gwyneth Paltrow shared the recipe of a daily shake on her online magazine's website goop — an almond milk-based concoction that includes a product from Moon Juice's line, with ingredients that are said to create a glowing complexion and healthy hair. Actress Jennifer Aniston also has said she puts collagen peptides in her morning shake.

And there's a movement by everyday people to incorporate natural products into their lives for everything from the foods they eat to dish soap and mascara they use. An entire generation of consumers has evolved from merely reading food labels to scrutinizing chemicals in everything.

DO THEY WORK?

“I think there's a perception of safer options, but I think it's exactly that. I think it's the peace of mind, too,” said Dan Fabricant, CEO of the Natural Products Association. “It's 'Hey, these are things that I'm used to in my diet. I'm going to prefer to do that than put on something that's from a chemical factory.”'

Doctors say skin is a detox organ and everything from poor diets to ailments can manifest there.

“If we are healthy inside, will our skin look better? Yes,” said Dr. Matthew Avram. But he counters that “it doesn't necessarily mean that because you take a certain supplement of one kind or another that your skin is necessarily going to look better.”