Effect alteration of Methamphetamine by amino acids or their salts on ambulatory activity in mice

Taking MSG with meth might make the high stronger, while L-arginine may be a double-edged sword.

  1. the elusive eye
    Study Author(s):
    Hisashi KURIBARA, Sakutaro TADOKORO
    Journal Name:
    The Journal of Toxicological Sciences, 1983, Volume 8, Issue 1, Pages 25-36
    Publication Date:
    This study from 1983 examines six amino acids and the changes they induce on the effects of methamphetamine in mice, as well as two other common substances. Monosodium L-glutamate (one of the isomers commonly known collectively as MSG), monosodium L-aspartate, and sodium bicarbonate (commonly known as baking soda) all augmented the effects of the meth in mice. Gamma-aminobutyric acid (GABA) and L-alanine had no effect on meth's activity. L-arginine HCL, L-lysine HCL, and ammonium chloride all attenuated the effects of the meth, and in a dose-dependent manner.

    All the substances that augmented the effects of the meth caused an increase in urinary pH, resulting in decreased elimination of meth, while all those that attenuated the effects caused a decrease in urinary pH, resulting in increased elimination. The authors speculate that the changes in excretion rates due to changed urinary pH may be responsible for the changes in methamphetamine's effects on mice.

    Of particular note is the effect of L-arginine HCL in attenuating meth's activity and decreasing urinary pH, with higher doses having a bigger impact; while many health-minded users use L-arginine to counter the vasoconstrictive effects of meth, it seems that doing so decreases urinary pH and therefore speeds meth's elimination from the body. With more meth being excreted unchanged, more quickly, it has less opportunity to act on the body, particularly in the brain, therefore having less effect - including those effects considered by users to be desirable.

    Conversely, monosodium L-glutamate and sodium bicarbonate both raise urinary pH, thereby decreasing the rate of meth's elimination and allowing it more time in the body to produce its effects; MSG and baking soda are both cheaply and commonly available at most markets, making them a cost-effective possible method for making one's meth last longer.