Caffeine is a stimulant that is used to stay awake and it gives mental alertness from fatigue. This is used as an adjunct for pain relief and also as energy accelerates. Caffeine is a non-prescription drug easily available as over the counter medication and comes in combination to acquire relief from headache and pain. Caffeine increases the mental alertness by offering the required energy for exercise training and weight loss. Caffeine cannot be considered as a mere stimulant as it reaches deep into muscles and provides power that is long lasting. Caffeine taken before any work out is also great as it fights the fatigue and keeps the person ready for the workout. Dieters also find caffeine as the solution as they feel sluggish. This is a no-calorie stimulant and does its job effectively and quickly. Caffeine anhydrous is found even in one or two coffee cups. However, this limitation is recommended as excess caffeine may result in irritability, rapid heart beat, nervousness and sleeplessness.

Citrus Aurantium is the Latin name for a citrus tree which grows bitter oranges. Traditionally being used by Chinese medicine and herbologists, the extract of the orange and the peel was used as a dietary supplement in concoctions with other herbs to suppress appetite. While other active ingredients of the citrus aurantium may contribute and even promote the effect, the main ingredient used in all weight loss products is synephrine, an alkaloid similar to ephedrine. It is a phenethylamine; it influences the alpha1 adrenergic receptor, constricting blood vessels, additionally increasing the heart rate and the blood pressure. In most cases the use of synephrine is paired with a diet and body building plan, where weight loss and muscle building is essential.

Synthetic Guggulsterones are derived from a herb, commiphora mukul, which has been proven to restore lagging metabolic rate brought about by dietary caloric deficiency, such as a diet low in carbohydrates. Though it has cholesterol lowering ability, it is also known as powerful weight loss agent due to the increased conversion of the inactive thyroid hormone T4 into its active part T3 in the liver. Furthermore, Guggulsterones are also known to stimulate the thyroid directly by enhancing TSH (Thyroid Stimulating Hormone) production. This is especially true for two specific guggulsterones codenamed Z and E.

Yohimbe- Basically a tree bark, Yohimbe is rich in pharmacologically active chemicals. It is commonly found in products developed for body building and enhancing male performance. The use of Yohimbe causes serious side effects too that include renal failure, seizures and in very rare cases, even death. Individuals suffering from low blood pressure, heart disease, liver or kidney disease, and diabetes should refrain from using any kind of Yohimbe supplements. Taking larger doses of Yohimbe can cause weakness, stomach disorders, fatigue, and nervous stimulation followed by paralysis. It is therefore important to avoid self-medication. Sometimes, side effects may arise even if small amounts of this supplement are taken, especially for prolonged periods. If you are already taking drugs for treating some health condition, it is best to avoid this supplement.