4-Methoxyamphetamine (Para-methoxyamphetamine, PMA) is a synthetic drug chemically similar to the recreational drug 3,4-methylenedioxymethamphetamine (MDMA or "ecstasy") and often replaces MDMA in tablets. Numerous cases of intoxication have been documented and fatal cases involving PMA have been described. PMA induces toxicity at lower doses than MDMA. Clinical symptoms specific to PMA poisoning include life-threatening hyperthermia, breathing difficulties, tachycardia, rhabdomyolysis, and acute renal failure. In the scarce studies conducted in laboratory animals, PMA has shown cardiovascular alterations in dogs, hyperthermia on a high ambient temperature, hallucinogen properties, and disruption of operant behavior in rats. A slight motor activity stimulation, lower than that induced by MDMA, has also been reported. The effects of PMA on brain neurotransmission are similar to those of MDMA, thus, PMA increases serotonin (5-hydroxytryptophan or 5-HT) release from the synaptic terminal and blocks its reuptake; it also acts upon noradrenergic and dopaminergic terminals but in a lesser proportion, and can also delay the metabolism of these monoamines by inhibition of monoamine oxidase (MAO)

Dihydroandrostenedione (Androstanedione) is a steroid metabolite and a precursor of both testosterone and estrone normally produced by the adrenal gland and gonads and is converted to testosterone through the action of 17β-hydroxysteroid dehydrogenase, which is found in most body tissues. Androstenedione is also produced by some plants and has recently been marketed as a product for increasing blood testosterone concentrations to be used as a natural alternative to anabolic steroid use. However, androstenedione administration during resistance training did not significantly alter the serum testosterone concentration in normotestosterogenic young men. The increased muscle size and strength observed with resistance training were also not augmented with androstenedione administration. The use of androstenedione increased the serum concentrations of estradiol and estrone, suggesting an increased aromatization of the ingested androstenedione and/or testosterone derived from the exogenous androstenedione. The use of androstenedione was associated with decreased levels of HDL-C. These data provide evidence that androstenedione does not enhance adaptations to resistance training and may result in potentially serious adverse health consequences in young men.

Didiavalo (premethadone) is a methadone analog and precursor. Didiavalo possesses analgetic properties with the effective dose in rats 30 times higher than the analgesic dose of morphine.