Viper Hyperdrive is a remarkable feel-good nutritional product, whose ingredients have rapid stimulant effects. Viper Hyperdrive utilizes Thermo-Rx, a unique phenylethylamine alkaloid blend from Acacia rigidula, and other potent stimulants that support energy, mood, and weight control. Viper Hyperdrive® works by mimicking the effects of our endogenous catecholamines such as epinephrine, norepinephrine and dopamine. A recent clinical study of Acacia Alkaloids showed that Acacia Rigidula Acacia rigidula extract, often called the ephedrine imposter, is the most effective metabolic stimulator on the market today! It is backed by “double-blind placebo controlled studies” and its effects were released at the Arnold Classic. Acacia rigidula displays beta-2 adrenergic receptor agonist activity. It is known that increased stimulation of beta-2 receptors will promote increased metabolic rate and thermogenesis. The findings of the study indicate that Acacia Rigidula promotes significant increases in resting energy expenditure (12+%) still evident 3 hrs post ingestion. When compared to 300 mg caffeine being at 3.5% at 3 hours post ingestion. The findings of the present study indicate that the increase in resting metabolic rate exhibited with Acacia Rigidula (12+%) are actually superior to the findings of previous studies which reported that 10 to 30 mg ephedrine increased energy expenditure by 6.6% to 10%.