This is a hard pill to swallow.

More than half of Americans take vitamins or other dietary supplements, according to The Council for Responsible Nutrition, and in 2015 alone, they spent $21 billion on them, according to HealthLine. So it’s no surprise that a rash of new companies are trying to get into the game — the newest among them promising vitamin regimens that are personalized to each customer’s needs.

Zenamins, MultiplyLabs and VitaMe are just three of the many start-up companies that offer these kinds of customized and personalized vitamin packs on a subscription basis that range in cost from a $25 two week trial to a flat fee of $39.95 per month for up to five specially formulated pills. By filling out a questionnaire that asks about goals, lifestyle, values and family health history, the companies are able to customize a packet of pills and capsules that target specific concerns.

This trend in personalized subscription vitamins comes on the heels of Gwyneth Paltrow’s March 2017 Goop Wellness launch. Known to many as the go-to guru for all things cool, Paltrow’s vitamin and supplement regimens — which are tailored to women’s needs — claim to help soften a multitude of ailments from fatigue to weakened immune systems and the perils of aging. The cost: $90 per kit or $75 if you subscribe monthly. And the company claims they sold over $100,000 of merchandise on the day they launched.

Gwyneth Paltrow (Photo by Phillip Faraone/Getty Images for goop)

But do we need personalized vitamin regimens? Probably not. “All critical vitamins and nutrients are contained in fresh fruits, vegetables, whole grains and low fat meat and dairy products,” says board-certified internist, Dr. Robert Huizenga. “Except for folic acid supplementation in pregnancy, there is no good evidence for health benefits from vitamins.” And a recent study at Johns Hopkins showed there’s no proof of benefit, but evidence of possible harm from high doses of certain vitamin supplements.

But for 30 year-old photographer Leif Edward French, subscribing to a custom vitamin and supplement program ensures that his money isn’t going to waste. “I’ve always bought supplements and vitamins but I’m the guy that buys them and then forgets to take them. This concept makes it so easy to dial in what you want each month and have it delivered in daily packs that are pretty hard to mess up,” says French.

At just $35 a month, his tailored packet includes a multivitamin, a probiotic, Vitamin B, Vitamin D and a brain supplement. “I’m only on my first month, but I’m loving it so far,” says French of Care/of, a company he discovered thanks to an ad that popped up on his Instagram feed.

While Dr. Huizenga discourages the use of vitamins in most cases — and has “ never taken vitamins myself” — he says they can help in cases when “someone is obviously low on an essential element or vitamin due to a medical condition.” But beware: “Personalized vitamins may be of theoretical value to those on restricted diets, however some studies show vitamins can have negative side effects and the false belief that vitamins can prevent the negative health effects of a lousy diet may paradoxically encourage poor eating habits,” says Huizenga.