Isabelle Ameganvi, leader of the women's wing of the group Let's Save Togo revealed that women are being asked to withhold sex from their husbands or partners.
She insisted that the strike would put pressure on Togo's men to take action against President.
Ameganvi, a lawyer revealed that her group is following the example of Liberian women, who used a sex strike in 2003 to campaign for peace, News.com.au reported.
"We have many means to oblige men to understand what women want in Togo," Ameganvi said.
The sex ban was announced at a rally in the capital city, Lome on Saturday, which saw thousands of people participating in it.
The demonstration was organised to protest recent electoral reforms, which is said to make it easier for Gnassingbe's party to win re-election in the parliamentary polls set for October.
The move has got millions of people in the country talking.
"It's a good thing for us women to observe this sex strike as long as our children are in jail now. I believe that by observing this, we will get them released," the paper quoted a woman, as saying.
"For me, it's like fasting, and unless you fast, you will not get what you want from God," she added.