Sure, you could certainly swallow too much St. John’s Wort and create the same type of serotonin or neurotransmitter issues you could create with a synthetic smart drug, but it’s far more difficult to harm yourself with a nootropic compared to a synthetic smart drug. Although synthetic, laboratory-designed nootropics do indeed exist, even those are not as harsh on the biology as a smart drug and have a mechanism of action that is a bit more natural. Let’s begin with the more natural nootropics.

There are a variety of substances to get magnesium from. Considerable enthusiasm for the new compound magnesium l-threonate was stirred by 2 small animal rat studies finding that magnesium l-threonate was able to increase magnesium levels in the brain and improve learning/memory tasks. (There are no published human trials as of October 2015, and evidence of publication bias, which I take as evidence against there being large effects in humans.) Animal studies mean very little, of course (see the appendix), but I thought it’d be interesting to try using l-threonate, so I bought the $30 Life Extension Neuro-Mag Magnesium L-Threonate with Calcium and Vitamin D3 (205g), which according to the LEF product page works out to ~60g of Magtein™ magnesium L-threonate and ~4.31g elemental magnesium inasmuch as LEF claims 2000mg of threonate powder provides 144mg elemental magnesium or a 14:1 ratio. (I don’t need the calcium or vitamin D3, but this was the only magnesium l-threonate on Amazon.) Experiment-wise, I’ll probably look at sleep metrics and Mnemosyne performance; I put off designing a blind self-experiment until after trying some.
Choosing to take smart drugs is not an effective or long term solution. Smart drugs may help you study faster or keep you awake longer, but they are not your best option. Most of the ADHD medications are based on an amphetamine structure and they are not healthy for your heart or your liver. Also, by taking smart drugs, you are putting yourself at considerable risk for addiction to these substances.

A recent study at the University of Innsbruck in Austria found that participants that drank two cups of coffee per day improved memory, reaction time, and neuron signaling, more than the control. More notably, the 676 daily coffee drinker participants experienced less mental decline than nondrinkers over a ten-year period. In other words, bottoms up on your cup of Joe!

The single most reliable way to protect our brain cells as we age, most researchers agree, is to eat plenty of fruits and vegetables, which are chock-full of antioxidants and nutrients. In a study published in the October 1997 issue of the American Journal of Clinical Nutrition, researchers tested 260 people aged 65 to 90 with a series of mental exercises that involved memorizing words or doing mental arithmetic. The top performers were those who consumed the most fruits and vegetables and ate the least artery-clogging saturated fat.
The main concern with pharmaceutical drugs is adverse effects, which also apply to nootropics with undefined effects. Long-term safety evidence is typically unavailable for nootropics.[13] Racetams — piracetam and other compounds that are structurally related to piracetam — have few serious adverse effects and low toxicity, but there is little evidence that they enhance cognition in people having no cognitive impairments.[19]