Former Blues and Scotland international Grayson Hart believes rugby has an "epidemic" with painkillers, claiming they're given to athletes "like lollies".
Hart, who played Super Rugby from 2008-13 before moving to the UK, told Stuff that team doctors would continually give him painkillers to cope with the pain of a degenerative knee injury.
But Hart, the nephew of former All Black coach John Hart, said he wasn't the only one who became addicted to pain medication.
"It got pretty bad, yeah," Hart told Stuff. "It even became a bit of a fun thing to do, pop a few and kick back on the couch, and get a bit of a buzz.
"Honestly, I wasn't too bad compared to some guys... I was definitely on the road to a dark place though. It's somewhat of an epidemic.
"I knew that, so [I] started looking for an alternative."
Hart has since recently launched a cannabidiol (CBD) company in the UK called Pure Sport CBD. The product made from cannabis helps athletes deal with pain and inflammation, without the addictive properties.
CBD oil is allowed under World Anti-Doping Agency (WADA) rules. His product company uses oil that is tetrahydrocannabinol (THC) free.
THC, the psychoactive element in cannabis, is still banned under WADA rules.
Hart hopes to bring his company to New Zealand to help Kiwi athletes deal with their injuries and overcome addiction.
"I started reading a bunch of stuff from elite athletes around the world, like Nate Diaz [UFC] and guys in the NFL, who swore by the stuff," Hart said.
"CBD, when done right, is a safe alternative to the drugs athletes are traditionally filled with. That stuff is not good and I have seen the dark side of it.
"My inflammation went way down and my sleep improved out of sight. I didn't feel anymore like I needed painkillers, which was a first in I don't know how long."
Hart's product has received high praise from former All Blacks Liam Messam, Jerome Kaino, Colin Slade and Victor Vito, who all currently play in Europe.