Experts have conducted studies that show that cannabis can affect the mechanism of action of estrogen-based hormonal birth control. Cannabis contains a major cannabinoid called tetrahydrocannabinol (THC) which causes a euphoric feeling when cannabis is used. THC affects the mechanism of action of estrogen-based hormonal birth control in the body. This happens by THC interrupting signaling between estrogen receptors. By interrupting this process, THC increases the estrogen level in the body countering the effects of estrogen-based hormonal birth control. This also increases the risk of blood lots and such persons developing stroke.