The cause of fibromyalgia is unknown; however, it is believed to involve a combination of genetic and environmental factors with half the risk attributed to each. The condition runs in families and many genes are believed to be involved.
Agonist: A substance that acts like another substance and therefore stimulates an action. Agonist is the opposite of antagonist. Antagonists and agonists are key players in the chemistry of the human body and in pharmacology.
drug agonist, a drug that is capable of binding to a neurotransmitter or hormone receptor and causing a response similar to the endogenous hormone or neurotransmitter.Compare antagonist.1  Facebook.rug agonist, a drug that is capable of binding to a neurotransmitter or hormone receptor and causing a response similar to the endogenous hormone or neurotransmitter.