Dendrobium extract is extract from Dendrobium nobile (member of orchid plant family) which is one of the 50 fundamental herbs used in traditional Chinese medicine as a therapeutic for nourishing the stomach, promote secretion of saliva, and reduce fever.
Why is dendorbium extract (Dendrobex™) added to pre-workout supplements?
Nowadays, dendrobium extract can be found in some pre-workout supplements (Driven Sports Craze, Gaspari Nutrition Detonate,…) in order to boost athletic performance. Some experts even say that it might be the next hot supplement. It is even argued to be a replacement for the stimulant dimethylamylamine (DMAA).
As the stimulant DMAA has been targeted by FDA, Dendrobium extract is trying to take its place. Dendrobium extract (as Dendrobex™) has been advertised as an energy replenisher and is said to be beneficial in rehydration. 
As of March 16, 2012, the manufacturer of a popular dendrobium supplement (Craze, Driven Sports) was the subject of a class action lawsuit which alleges that the product contains amphetamines and that the product is manufactured in non-compliant facility. While dendrobium might have some advantages over DMAA, experts suspect that some dendrobium extracts might be spiked with synthetic stimulant drugs. Craze by Driven Sports contains the stimulant phenylethylamine (stimulant with effects are similar to amphetamine ) which some experts say does not occur naturally in dendrobium plants.  However, according to Terence A. Smith  phenethylamine is widely distributed throughout the plant kingdom. Phenethylamine releases norepinephrine and dopamine  and has been implicated in modulating mood and affect .
Dendrobium extract side effects and safety concerns
Dendrobium contains several chemicals that might have effects in the body. They might lower blood pressure, increase blood sugar, and reduce pain. None of these effects have been studied in humans. There isn’t enough information to know if dendrobium is safe or what side effects it might cause .
- Meet DMAA’s replacement: Dendrobium extract Retrieved from http://newhope360.com/ 20. Feb 2013
- Is DMAA successor dendrobium legit? Retrieved http://newhope360.com/ 20. Feb 2013
- Parker, ERIC M., and LUIGI X. Cubeddu. “Comparative effects of amphetamine, phenylethylamine and related drugs on dopamine efflux, dopamine uptake and mazindol binding.” Journal of Pharmacology and Experimental Therapeutics 245.1 (1988): 199-210.
- Dendrobium Overview Information Retrieved from WebMD.com 20. Feb 2013
Smith, Terence A. “Phenethylamine and related compounds in plants.” Phytochemistry 16.1 (1977): 9-18.
Grimsby, Joseph, et al. “Increased stress response and β–phenylethylamine in MAOB–deficient mice.” Nature genetics 17.2 (1997): 206-210.
- Dr. Duke’s Phytochemical and Ethnobotanical Databases. Retrieved from ars-grin.gov 20. Feb 2013