The strongest OTC products with diuretic properties available on the market as of June 2015 are those that contain caffeine as one of the main ingredients, according to Diet.com. Other less potent options that increase the volume of urine production include herbal remedies and pamabrom preparations.
Caffeine-containing products such as NoDoz are often used as stimulants, and the effectiveness of caffeine as a diuretic depends greatly on the amount that is used. However, care should be taken as in very high doses the compound can cause a state known as caffeine intoxication that can lead to nausea, coma, convulsions and, in the most extreme cases, death, Diet.com reports.
An alternative method is to use herbal diuretics. Mayo Clinic suggests that herbs known for strong diuretic properties include dandelion, ginger, parsley and butchers broom. Again, the effect depends on the regularity of use and the concentration of any preparation used. Care should be taken to source herbs from a reliable source.
While not the strongest OTC diuretic product available, one of the safest is pamabrom. It is most commonly used for premenstrual bloating and fluid retention. Pamabrom, a breakdown product of caffeine, is the main ingredient in OTC medications, such as Tylenol for women, Duirex and Backaid.