Caffeine

The oldest, most common, and most likely safest stimulant to use.

In modern western society, even below the age of 10 children have caffeine tolerances built up from sodas and sweet tea.  At some point in your life, you have ingested caffeine in some way.

The most interesting facet of caffeine's action on the body is that it is both lipid and water soluble, so that it permeates the blood brain barrier very efficiently.

Its less important to understand the biology behind caffeine as it is to understand which dosages do what.  200-300 mg dosage is handy for a few hours of good focus. above 500mg, GABA transmission is inhibited in a significant way, and above 1000mg, usually severe irritability and intensified anxiety occurs.  Dosages from 2-3.6 grams will cause toxicity in a 200 pound adult.

Benefits of caffeine supplementation:

Increased anaerobic capacity

Increased power output

Anti fatigue effects

Slight increase in testosterone (12% on average with 250mg taken before workout)

Increased metabolic rate (EC stack and its variants will be detailed later)

While there are many more benefits and a few insignificant drawbacks in training, it has a few mental benefits.  The anti fatigue effects help attention span and GABA inhibition helps prevent sleepiness.

Caffeine is a fairly tame stimulant overall, so I have no extreme stories to report. Personally I use it as a base for most of my dosing protocols, along with piracetam.  For sleep avoidance, I line up dosages of stimulants so that there is an immediate and continued effect.  Phenylethylamine, a fast acting neurotransmitter; Caffeine, to take over after the PEA wears off, and then Adrafninil, which begins to kick in as the caffeine edge dulls.

Final Verdict

Caffeine is always a buy and a must have for anyone* with any goal. It is dirt cheap and incredibly versatile.

*Do not use if you have a history of heart problems, as stimulants can exacerbate arrhythmia and other conditions.  Central Nervous System (CNS) stimulants can also cause heart palpitations, a scary occurrence. Always keep dosage within reason, and know yourself very well.