'Write what you know' is advice commonly given to writers by their peers. Author Gerry Mullins has done just that with his latest novel, Testosterone, Dublin 8. Gerry told Ryan Tubridy on Wednesday that he's been taking the hormone himself for the past two years, on medical advice. It follows an extended period of "not feeling the best about life". His GP did some tests and determined that his testosterone levels were low and prescribed a supplement of what is classed as an anabolic steroid, something Gerry can laugh about:

"So I was now juicing, in the same way as a professional cyclist may have done in the past, you know?"

Gerry decided to research the hormone while continuing to take it and it was during his research that he sketched out the bones of a story about "a regular guy" who starts taking testosterone. Initially, this works well for his character (well, well-ish):

"He's feeling very bad about himself. He starts taking it and then starts feeling much better about himself. Next thing he finds himself much more macho, starts taking cocaine and then the downside of testosterone, if you're feeling very macho and all that, that's great. But one of the downsides is the recklessness."

The book attempts to resolve the issue of whether a man needs to be "low-testosterone and wimpy" or "high testosterone and a bully", or if there's some happy medium in between. But Ryan wanted to know about the non-fiction story of Gerry's own experience with the steroid. Did it solve the issues he was having? There's no straight answer. Gerry does suffer less from anxiety than he used to, but, when he started taking the hormone, he also made significant changes to his lifestyle, including giving up alcohol, eating healthily and getting a decent night's sleep. He does feel better. But is that because of the changes he made, the testosterone he's taking, or a combination of the two?

"I think that I'm probably a little bit more prone to anxiety than other people and I think perhaps the anxiety caused the depleted testosterone… Originally, if you'd asked me two years ago, I would've thought that the depleted testosterone had led to anxiety, but I'm kinda coming round to the other way around now."

So… it's complicated. Ryan asked Gerry about the goal of taking the supplement – what did he want to achieve by taking it?

"To feel better. More confident, more energetic, more ambitious, more focused. It was those things that I was lacking and it was to reverse those."

To hear the full chat between Gerry and Ryan – including how to apply testosterone, the potential side effects of taking it and the dangers of 'roid rage – click here.

Testosterone, Dublin 8 by Gerry Mullins is published by Liberties Press.

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