UPDATE: Despite a report claiming that Efron had undergone two stints in rehab, a source insists that the actor in fact only underwent treatment one time, as E! News originally reported.
The Parks and Recreation star served up some words of wisdom on Twitter Wednesday, and while he doesn't mention 25-year-old Efron by name, it's probably safe to say we know who he's talking about given their friendship.
"A thought: if you only find out a person has been to rehab weeks or months after they got out, they're probably serious about recovery," Lowe tweeted.
It's certainly a nice sentiment when you consider that the 49-year-old actor celebrated 23 years of sobriety earlier this spring.
The two have been pals for several years now. In fact, Lowe recently posted a Vine video showing Efron celebrating the Fourth of July holiday with Lowe and his family. Fireworks and all!
Earlier this week, sources told E! News exclusively that Efron had actually gone through rehab about five months ago.
"He's healthy, happy and not drinking," one souce said. "He's taking time to focus on working."
At the Toronto International Film Festival, Efron attended the premiere of Parkland, his upcoming ensemble drama about the JFK assassination.
"I'm good, real good," he said.
(Originally published on Sept. 19, 2013, at 10:14 a.m. PT)