20-Hydroxyecdysone and other ecdysteroids are used in biochemistry research as inducers in transgenic animals, whereby a new gene is introduced into an animal so that its expression is under the control of an introduced ecdysone receptor . Adding or removing ecdysteroids from the animal's diet then gives a convenient way to turn the inserted gene on or off (see ecdysone receptor ). At usual doses, 20-hydroxyecdysone appears to have little or no effect on animals that do not have extra genes inserted; it also has high bioavailability when taken orally, so it is useful for determining whether the transgene has been taken up effectively.  For uses in gene therapy , it may be necessary to investigate more thoroughly the natural sources of ecdysteroids in humans (which appear to include dietary phytoecdysteroids , gut flora , helminth infections , and other diseases ). 
Ecdysteroids from Ajuga reptans L. were applied to leaf fragments by immersion in aqueous solution of the compounds or by addition to the culture medium. A high mortality rate of first larval instars was detected with 29-norsengosterone and ajugalactone treatments. This effect was specially pronounced when the products were incorporated in the medium. A significant increase in mortality was also recorded in the pupal state with a 20-hydroxyecdysone treatment. This effect was never observed before, because all whitefly larvae on A. reptans leaves die in the first larval instar.
The purpose of this study was to elucidate the role and relative importance of steroids in Vitex species in controlling An. gambiae larvae and to use this information in guiding effective development of formulations to be used in integrated pest management programmes. Three variants of blend effects were noted from these results. First, production of a less active blend from active constituents; secondly, enhancement of the activity of a moderately active compound by an active constituent and; thirdly, synergism between moderately active compounds to give a blend that was more active than the individual constituents. The first variant was illustrated by the high lethal activity of compounds 1 and 2 while the second was illustrated by the enhancement of the activity of compounds 3 and 4 in blends with 1 and 2 . The third variant was illustrated by the combination of compounds 3 and 4 .