Jordan Spieth has said that he believes hemp oils and creams can help professional golfers with their aches and pains but is concerned that lack of regulation of the products could lead to a player failing a drug test.
Spieth and Rory McIlroy, both recent world No. 1 players, said they are mindful that hemp and cannabidiol (CBD) products might contain small amounts of THC, the principal psychoactive constituent of cannabis and a banned substance on tour.
"That stuff's been kind of known to really help with what we do, you know, shins and feet and that kind of stuff and ... helping to recover," said Spieth at the Zozo Championship in Japan.
"Hemp's not banned, but THC is, so it's kind of a fine line there. It's so early on where some of it has THC levels and some of it doesn't."
The Texan said that he hopes regulations will emerge to make it "easier to figure out what's in everything."
Commissioner Jay Monahan said on Wednesday the tour would continue to base its banned list on the strict World Anti-Doping Agency (WADA) guidelines.
The tour implemented drug testing in 2008, in large part to aid its ultimately successful quest to become an Olympic sport.
CBD and hemp oils, which are legal, are extracted from plants in the same family as marijuana. The products have gained in popularity on tour the past couple of years, even though there is little, if any, guarantee they will not contain small amounts of THC.
"I'm very aware of the banned substance list," world No. 2 McIlroy said.
"I'm very careful what I put into my body. I even wouldn't be comfortable taking CBD oil. I would be too paranoid that there would be THC in it and then that could lead to a positive test.
"I am the most conservative on everything. I try not to take anything in terms of pills to help in any way. I'm even scared to take painkillers sometimes, like Advil [Ibuprofen].
"I think we've been very clear with our players that because CBD oil and CBD as a product is an unregulated product, it essentially is a supplement, with it comes risk.
"So we've ... tried to communicate that risk to our players.
"But ultimately, we don't determine what is a banned substance and what's not. We rely on WADA for doing that, so we'll continue to stay very close not only to that substance but any potential substance that would come on or come off the list."