Though Charlie Sheen’s HIV has been described as “completely manageable,” the actor recently shared that he once came across a treatment he believed worked far better than existing options, but it never reached the public. Speaking on the *Howie Mandel Does Stuff* podcast, the 60-year-old actor reflected on an experimental drug he used years ago and explained why it ultimately disappeared from view. “There was one that was really good that I was hoping would come to market one day, and it never did,” said Sheen, who publicly disclosed his HIV diagnosis in 2015. This has raised a key question: which experimental drug is Charlie Sheen referring to?What Is HIV?Human immunodeficiency virus, or HIV, is a virus that attacks the immune system. If left untreated, it can progress to acquired immunodeficiency syndrome, or AIDS, which represents the most advanced stage of infection. HIV primarily targets white blood cells, weakening the body’s natural defences. The virus spreads through unprotected sexual contact, sharing needles for drug use, exposure to infected blood, and from parent to child during pregnancy, delivery, or breastfeeding.What Does HIV Do To A Person?HIV infects CD4 cells, also known as helper T cells, which play a central role in immune response. As the virus destroys these cells, the white blood cell count drops, leaving the body vulnerable to infections it would normally fight off with ease.Early on, HIV can cause flu-like symptoms. After that, it may remain hidden in the body for years without obvious signs, while continuing to damage the immune system. When CD4 levels fall very low, or when certain serious infections develop, HIV is considered to have progressed to AIDS.At this stage, symptoms may include rapid weight loss, severe fatigue, sores in the mouth or genitals, recurring fevers, night sweats, and changes in skin colour.Charlie Sheen Claims An Experimental Drug That Works Better For HIVDuring the podcast conversation, Sheen named the drug he believes made a major difference. “That was a thing called PRO 140,” he said. He described it as a monoclonal antibody that produced faster and more consistent results, with fewer side effects than standard treatments. When asked why it never became widely available, Sheen suggested it may have posed a threat to existing therapies. “It works, better than what they have,” he said, adding that the company behind it ran into serious trouble. Mandel responded that someone should investigate further, a point Sheen agreed with.What Is The Experimental Drug Charlie Sheen Is Talking About?PRO 140 is a humanised monoclonal antibody designed to block CCR5, a receptor HIV commonly uses to enter human cells and replicate. Around 70 percent of people living with HIV in the United States, and as many as 90 percent of newly diagnosed patients, carry CCR5-tropic strains of the virus.Earlier studies found that a single intravenous dose of PRO 140 sharply reduced HIV levels, while weekly injections under the skin lowered viral load much more effectively than a placebo. Research also suggested that the drug did not interfere with normal immune functions linked to CCR5.According to Aidsmap, PRO 140 was generally considered safe and well tolerated. Although more than 90 percent of participants in extended studies reported side effects, there were no serious adverse reactions linked directly to the drug, and no one had to stop treatment because of it. The reported side effects were limited to injection-site reactions, which were usually mild to moderate.Sheen has repeatedly spoken about his experience with the drug, maintaining that it delivered steadier results and caused fewer side effects than conventional HIV treatments.