The Food and Drug Administration is planning to more aggressively regulate homeopathic drugs that are potentially harmful and unproven, reversing nearly three decades of policy.

Homeopathic remedies use ingredients that can be dangerous, but are so diluted they're said to be safe and even cure illnesses. The FDA decided in 1988 that it would not use all the enforcement authority within its power to regulate such products.

However, within the past decade, more people have experimented with homeopathic remedies. The once-small industry has ballooned to $3 billion, the FDA said. In proposed guidance, the agency said it's changing its stance because as the industry has grown, and so has the risk.

The FDA plans to target products that are meant for vulnerable populations like infants and children, those that don't cure the serious illnesses and diseases they're said to, and those that contain potentially harmful ingredients and don't meet good manufacturing processes.

"Our approach to regulating homeopathic drugs must evolve to reflect the current complexity of the market, by taking a more risk-based approach to enforcement," FDA Commissioner Scott Gottlieb said in a statement. "We respect that some individuals want to use alternative treatments, but the FDA has a responsibility to protect the public from products that may not deliver any benefit and have the potential to cause harm."

Homeopathic products drew national attention last year when 10 children died and 400 experienced adverse effects, such as seizures, after taking some over-the-counter teething medicines. The FDA issued warnings against using these remedies, which contained dangerous levels of belladonna, a toxic ingredient.

Some retailers pulled products from shelves. Standard Homeopathic Co. discontinued its Hyland's teething products, saying in a statement that the FDA's warning "created confusion among parents and limited access to the medicines." It later recalled the products after FDA lab testing found its products and CVS' contained inconsistent levels of belladona.

The proposed policy would clarify how the agency would exercise its enforcement authority. The agency could send warning letters to companies whose products don't work like they say they do. Even if the products may not harm patients, they may not help and even prevent them from receiving other treatments.

"In many cases, people may be placing their trust and money in therapies that may bring little to no benefit in combating serious ailments, or worse — that may cause significant and even irreparable harm because the products are poorly manufactured, or contain active ingredients that aren't adequately tested or disclosed to patients," Gottlieb said in a statement.

The decision comes one year after the Federal Trade Commission announced it would require over-the-counter homeopathic drugs to provide scientific evidence for health-related claims.

The FDA began reviewing its approach to regulating homeopathic drugs in 2015. It will now open the proposal to public comments for 90 days and will then take those under consideration before issuing its final policy.

In the meantime, the FDA plans to start being more proactive in enforcing homeopathic products that fall under its priorities outlined in the new policy.