The musician, real name Austin Richard Post, spoke out about the incident during his live show at the FedExForum in Memphis, Tennessee on Friday (6 March), where he told the crowds of adoring faces not to worry.
The rapper said: "I'm not on drugs! I feel the best I've ever f***ing felt in my life.
"And that's why I can bust my a** for these shows and f***ing fall on the floor and do all that fun s***. But for anyone that's concerned here, I appreciate the love and the support, but I feel f***ing fantastic and I'm not doing drugs."
Fans had begun to speculate about New York-born star's health after a number of videos had circulated on Twitter.
One fan shared a video of him rolling around, which was cause for concern, saying: "I'm genuinely concerned for Post Malone and his well-being right now."
This promoted others to join the conversation. The short clip, shared on Twitter, has had almost half-a-million views to date, over 7,000 retweets, and 28,000 Likes.
Viewers continued to speculate about the reason behind Post Malone's on-stage antics following this latest announcement.
One wrote: "It could just be exhaustion. Either way, he needs to take a break and take care of himself."
Another was just grateful the rapper has said he's OK, commenting: "Thanks for sharing. I will be able to sleep tonight."
A third wrote: "This makes me genuinely so happy."
The rapper is currently embarking on his Runaway tour which began last September in Tacoma, Washington. He is on his way to Europe this summer where it will conclude on 2 July at London's Hyde Park.
Words: Mike WilliamsFeatured Image Credit: PA