Finn Russell uses it to help him sleep. Jerome Kaino takes some to ease knee pain. While Jim Hamilton needs it to cope with the aches he still lives with five years after retiring.
Cannabidiol, or CBD, is relied on by the British and Irish Lions fly-half, the two-time All Black World Cup winner, and the former Scotland lock – among many others – to manage the pain inflicted by the brutality of the sport.
But what is it? How does it work? And is it safe? In the first of a two-part series, BBC Scotland examines the role of the cannabis extract in rugby.
Why are players using it?
Rugby is one of the most physically demanding sports there is. And, with players getting bigger and stronger all the time, the pressure on their bodies continues to grow, particularly in a crowded calendar.
Strength and conditioning, nutrition, and sleep are the main methods of recovery. But often that’s not enough, so players turn to painkillers ranging from common anti-inflammatory tablets, to powerful opioids such as tramadol.
Kaino, who won the World Cup with New Zealand in 2011 and 2015 and is known for his thumping tackles, “always” used anti-inflammatories to back up training sessions and matches.
“You’d be surprised at the numbers of players that do resort to those or the odd stronger painkiller to try to get rid of a few bumps and bruises,” the 38-year-old tells BBC Scotland.
“I had a huge reaction to anti-inflammatories. I’d always have gut problems but to be able to get the joints feeling right I had to be able to take them every now and then.”
“In the hemp plant there’s well over 100 cannabinoids,” says Professor Close. “Only one of them isn’t prohibited by Wada and all the others are.
“So if an athlete is taking CBD, we need to know that they’re taking it from a source where we know there are no other cannabinoids in there that would fail an anti-doping test.”
The company Informed Sport tests supplements and is commonly considered as the gold standard for products in the UK, but they currently do not accept CBD products. It remains to be convinced of its safety from a doping perspective.
But the industry is predicted to be worth $20bn (£14bn) by 2024, and athletes across sports continue to use, promote and invest in CBD products.
“When I was younger, instead of taking drugs I would go down the herbal route,” Russell says. “So it’s similar to that. I’ve had that my whole life and it’s just another level of it for me in the current stage of my career.
“It’s come from a plant so what’s to say it’s any different from other things that you get? It’s up to the individual what they want to do, but for me I’ve got no concerns about taking it and I’ll continue taking it.”
Could CBD become ‘like protein shakes’? Find out more in part two on Thursday