Generally, never. Because any small change in chemistry is something that evolution is very effective at picking up. Which means that if there is a simple intervention that improves performance, there is always a good reason why nature hasn't already given it to you. In the case of EPO, it's significantly increased risk of blood clots and blood pressure related conditions.

Many of these drugs were developed and used as medical products before being adopted by athletes.

EPO is used in medical conditions.

Several anabolic steroids are prescription drugs and can be used in cases of muscle wasting or cancer.

Most people don’t understand the consequences that come with using these drugs. They’re often not a free lunch where you take the drug and become a better human being across the board. There are negative consequences for altering the body’s systems directly in most cases.

In medical conditions doctors can weigh the tradeoffs and use drugs sparingly to achieve an outcome while monitoring the negative effects. When a 20 year old gym bro starts juicing with excessive doses to get swole, they’re not thinking about how it’s going to damage their testes for the rest of their life or disrupt their HPTA axis.

I prolonged the life of my terminally ill dog using EPO. It wasn't exotic or expensive. Probably that means it's already in wide use for humans, too.

Medical uses typically come before any performance enhancing ones.

What helps you get a little more oxygen to you muscles thus winning the race is worth nothing to someone pushing a shopping cart around Costco.

No can do, that would be bad for coca cola and starbucks sales.