Google will allow ads for stem cell treatments that are approved by the US Food and Drug Administration — a change from its previous policy, which banned all ads for this experimental category of medical care. The policy update was first reported by Gizmodo and will go into effect in July.

The company said in the policy update that it will also allow cell or gene therapy ads that are “exclusively educational or informational in nature,” even if they reference products or applications that are not approved by the FDA. It’s not clear how Google would define “educational” or “informational” or what type of advertisements would be allowed under that umbrella.

Stem cell therapy is a broad term for medical treatments that use stem cells, which can develop into any cell type. There are some evidence-based applications for the cells, like to treat some cancers, and there are around two dozen FDA-approved cell- and gene-therapy products (which Google’s new policy would allow ads for).

But most uses for stem cells are unproven, experimental, and can be dangerous. Clinics claim the cells, taken from donated umbilical cords or from patients’ fat, can treat things like joint pain or eye conditions. People have developed infections and died after getting those types of procedures. The FDA has tried to crack down on businesses offering these types of procedures, but they’ve proliferated over the past few years.

Google’s initial ban on stem cell ads hasn’t done much to keep the clinics from popping up in search, Paul Knoepfler, a professor at the UC Davis School of Medicine, wrote in Stat in March. Even if they can’t advertise, the companies have designed websites that appear at the top of search results for searches related to stem cells — above more reputable medical resources, like the National Institutes of Health.

These companies are savvy and have been able to skirt policies to push out their products even in the face of a total ban. Now, that ban is set to relax, opening up new avenues for groups to distribute information. “Google’s continuing stem cell problem is emblematic of a serious, broader problem with unproven biomedical offerings the company needs to address,” Knoepfler wrote.