WASHINGTON (AP) — Federal health officials are taking aim at telehealth companies promoting unofficial versions of prescription drugs — including popular weight loss medications — as part of the Trump administration’s crackdown on pharmaceutical advertising.

The Food and Drug Administration earlier this week posted more than 100 letters to various drug and online prescribing companies, including Hims & Hers, which has built a multibillion-dollar business centered around lower-cost versions of blockbuster obesity injections.

The FDA warned the company to remove “false and misleading” promotional statements from its website, including language claiming that its customized products contain “the same active ingredient” as FDA-approved drugs Wegovy and Ozempic.

The formulations cited by regulators are produced by specialty compounding pharmacies and aren’t reviewed by the FDA.

“Your claims imply that your products are the same as an FDA-approved product when they are not,” states the warning letter, dated Sept. 9.

It’s the first FDA attempt to directly police online platforms such as Hims, which have long argued they’re not subject to drug advertising rules.

A memo signed by President Donald Trump last week directed Health Secretary Robert F. Kennedy Jr. and the FDA to ensure that pharmaceutical ads on TV, social media and other websites are “truthful and non-misleading.”

As part of the initiative, the FDA promised to send 100 letters to companies with deceptive ads.

The new FDA letters each contain “cease and desist” language. That’s a different approach for the agency, which typically drafts its letters in highly bureaucratic language citing specific FDA regulations.

Hims has been under scrutiny from Washington for months.

Earlier this year, a Super Bowl ad from the company touted the benefits of its weight-loss medications but didn’t list any of their side effects or potential harms. FDA rules require advertisements to present a balanced picture of drug risks and benefits.

FDA Commissioner Marty Makary noted an ad in last week’s Journal of the American Medical Association, calling it a “brazen” example of how advertising is “contributing to America’s culture of overreliance on pharmaceuticals for health.”

San Francisco-based Hims did not immediately respond to requests for comment.

Hims and similar companies initially sold cheap generic versions of drugs for hair loss, erectile dysfunction and other health issues, but booming demand for obesity medications opened the door to selling cheaper copies.

The FDA permits so-called compounding, or customized production, when there is a shortage of the official versions of FDA-approved medications.

The FDA recently determined that the GLP-1 drugs no longer met the criteria for a shortage. That should have ended the compounding, but there is an exception: The practice is still permitted when a prescription is customized for the patient.

Hims and other companies have taken to offering “personalized” dosages and formulations for certain patients, arguing they offer extra benefits.

The letters posted this week come from the FDA’s drug center. A letter posted last week from the FDA’s vaccine division took issue with a TV ad for AstraZeneca’s FluMist vaccine, saying the spot’s “background music and visual distractions” detract from information about side effects.

The letter was signed by FDA vaccine chief Dr. Vinay Prasad, who recently returned to his job at the agency.

Researchers and consumer advocates have long complained that the TV images of patients enjoying life with family and friends often overshadow discussions of side effects. Studies have also shown that patients exposed to drug ads are more likely to ask their doctors about the medication, even if they don’t fit the prescribing criteria.

The American Medical Association, the nation’s largest physician group, came out in support of a ban in 2015.