Is taking stimulating pills forbidden or permissible?

If wakefulness pills cause harm, then it is not permissible to take them, based on the Prophet’s (peace be upon him) saying: "There shall be no harm or reciprocating harm." Likewise, it is not permissible to take them if their consumption leads to committing a forbidden act or neglecting an obligatory duty. Among the jurisprudential rules are: "Whatever leads to the forbidden is forbidden," and "The means to a thing is like the thing itself." However, if they are free from harm and are used to assist in an act of obedience or something permissible, then there is no objection to them.