The 26-year-old Toulon player was last week informed that he tested positive for the prohibited substance morphine after the Top 14 final defeat by Toulouse on June 9.
He was provisionally suspended ahead of his appearance before the French Rugby Federation's anti-doping commission on August 21, but has now been cleared to feature in his club's remaining pre-season friendlies.
A statement on club website www.rctoulon.com read: "Temporarily suspended pending a hearing before the anti-doping commission on August 21, the Toulon flanker has had his penalty lifted and is therefore able to play the last two friendly matches with Rugby Club Toulonnais.
"Nevertheless, he will still be called before the commission to fight the case against doping on August 21."
Armitage and Toulon expressed their confidence the player would clear his name.
The club insisted the "abnormal" test result was caused by a side-effect of painkillers and anti-inflammatories prescribed for back pain, which they say are approved by the French Anti-Doping Agency (AFLD), while Armitage vowed he would come back stronger.
The five-cap international said last week in a press conference broadcast on the club's website: "It's a bit stressful, especially for my family in England.
"But I will keep my head held high because I have done nothing wrong.
"I know that everything will soon be sorted, that I will be able to forget about this and come back stronger."
- French Rugby Federation
- Rugby Club Toulonnais