A number of pharmaceutical companies are running experiments in attempts to create the next generation of psychedelic drugs, with the goal of turning them into a safer psychotherapy treatment.

As Time reports, researchers at a company called MindMed are working on an alternative to MDMA, (i.e. “ecstasy” or “molly”) called R-MDMA. Early data has shown that R-MDMA has fewer side effects than its predecessor, thus enhancing its potential as a therapeutic drug.

Other companies are working on taming other psychedelic drugs — like one attempting to create a synthetic version of the “spirit molecule” DMT — to provide longer-lasting relief for people suffering from depression.

These drugs’ potential to provide psychedelic experiences that meaningfully improve mental health remains a hotly debated subject, especially considering the potential of an unwanted “bad trip.” But the use of psychedelics within the context of mental health, used under a controlled setting, has seen a huge influx of interest over the years. While MDMA is still classified as a Schedule I substance — per the DEA, a dangerous drug with no accepted medical use — several studies have found the drug could be an effective way to treat conditions like post-traumatic stress disorder or depression.

Beyond America, countries like Portugal and Amsterdam have decriminalized small amounts of MDMA for personal use, and last year, Australia greenlit government-sanctioned legal trials of MDMA for PTSD treatment. Despite the surge of interest, scientists are only starting to understand how these substances alter our brain chemistry.

“Psychedelics are very promiscuous molecules,” psychedelic drug development company Mindstate CEO Dillan DiNardo told Time. They’re “very effective, but they’re scary and they’re chaotic and they’re unpredictable.”

One factor distinguishing Mindstate is their plan to use artificial intelligence to figure out how psychedelic drugs affect the brain. And its efforts are seemingly starting to pay off. Last month, the company received approval to kick off human trials of a compound dubbed MSD-001 by the US Food and Drug Administration. The substance dubbed “Moxy” targets “specific serotonin receptors with high specificity, minimizing broader psychotropic effects,” according to Microdose.

“Moxy is not the entire medicine,” DiNardo told the Washington Post at the time. “Moxy is the first part of a number of different medicines that we’ll be making.”

Companies like Mindstate and MindMed have a long way to go until their synthetic psychedelics can be prescribed by health practitioners. Human trials will likely drag on for many years, and it remains unclear if they’ll ever prove to be effective. But advocates of psychedelic therapy may view this as a small (but meaningful) step forward.

More on psychedelics: Scientist Takes High Dose of Psilocybin, Clambers Into MRI Machine to Scan His Own Brain