Thymol, a monoterpene, obtained from thyme oil or other volatile oils, is used as a stabilizer in pharmaceutic preparations. It has been used for its antiseptic, antibacterial, and antifungal actions to help reduce and prevent plaque and gingivitis. Recently was shown, that this substance was able to significantly reduce the oxidative stress associated with cataract. The results suggested that thymol might be a potential therapeutic approach in the prevention of diabetic complications through its aldose reductase enzyme inhibitory and antioxidant activities.

Quinine ascorbate is a salt of antimalarial drug quinine and ascorbic acid (vitamin C). Ascorbate reduces the potency of quinolone-containing anti-malarial drugs. Quinine ascorbate was marketed as a component of over-the-counter smoking deterrent products but was not recognized as safe by the FDA regulation in 1993.

Silver iodide is an inorganic compound with the formula AgI. It is used as a photosensitive agent in photography, as a local antiseptic, as a chemical intermediate, and in cloud seeding for rain-making. The major hazards encountered in the use and handling of silver iodide stem from its toxicologic properties. Effects from exposure may include skin rashes, conjunctivitis, argyria (a permanent ashen-gray discoloration of skin, conjunctiva, and internal organs), headache, fever, hypersensitivity, laryngitis, and bronchitis.

Lobeline is an alkaloid found in "Indian tobacco" (Lobelia inflata), "Devil's tobacco" (Lobelia tupa), "cardinal flower" (Lobelia cardinalis), "great lobelia" (Lobelia siphilitica), and Hippobroma longiflora. Additionally, it is also found in Lobelia Chinensis. In its pure form, it is a white amorphous powder which is freely soluble in water. Lobeline has been sold, in tablet form, for use as a smoking cessation aid, and may have application in the treatment of other drug addictions such as addiction to amphetamines, cocaine, or alcohol. Lobeline has multiple mechanisms of action, acting as a VMAT2 ligand, which stimulates dopamine release to a moderate extent when administered alone, but reduces the dopamine release caused by methamphetamine. It also inhibits the reuptake of dopamine and serotonin and acts as a mixed agonist-antagonist at nicotinic acetylcholine receptors to which it binds at the subunit interfaces of the extracellular domain. It is also an antagonist at μ-opioid receptors. It seems to be a P-glycoprotein inhibitor, according to at least one study. It has been hypothesized that P-glycoprotein inhibition reduces chemotherapeutic resistance in cancer, presumably affecting any substrates of P-gp.