Guarana- General caffeine source, this is easily ruled out because caffeine is the stimulant we are looking to avoid in this experiment
Ephedrine- A stimulant that works on the central nervous system, concerns about its effects on the heart, also easy to rule out as it is also a stimulant.

B-vitamins- A group of vitamins that can convert sugar to energy and improve muscle tone, improve alertness.
Inositol- A member of the vitamin B complex (not a vitamin itself, because the human body can synthesize it) that helps relay messages within cells in the body.
Taurine- A natural amino acid produced by the body that helps regulate heart beat and muscle contractions. Many health experts aren't sure what effect it has as a drink additive.
Carnitine- An amino acid that plays a role in fatty acid metabolism.
Creatine- An organic acid that helps supply energy for muscle contractions.

Ginseng- A root believed by some to have several medicinal properties, including reducing stress and boosting energy levels.
Ginkgo biloba- Made from the seeds of the ginkgo biloba tree, thought to enhance memory.

Energy drinks last about 5 hours in the body
The main ingredient with an effect is caffeine
It takes about 45 min for an energy to come into effect after drinking, mostly because that is how long it takes for caffeine to metabolize.

Taurine seems to be the most likely candidate to increase energy levels (outside of literal stimulants). Taurine has some evidence of both increasing general energy levels and alertness. It has also been associated with aiding in a number of minor amino acid deficiency issues, which is generally good.

B vitamins improving alertness is a controversial claim, as in they likely do not cause a noticeable increase in alertness unless there is a deficiency in the body.¹⁾ But may be able to increase the ability to concentrate and likely have benefits in increasing your metabolic rate, which may cause greater alertness across time.

Lets review the stimulants (even though we wont be using them here) Ephedrine- main source is not American Ephedra species but instead ma huang- Ephedra sinica from china. As a stimulant, ephedrine is addictive, and has many negative effects on heart health as well as effects on other medications. If this is to be used it is both sparingly and not over a long period of time as the addictive effects are accumulative. There does not seem to be major negative side effects of drinking Ephedra tea, as the dosage is low and the concentration of the ephedrine and related compounds is relatively low.

Caffeine- I want to keep caffeine separate from the other ingredients in this work, it is the most easily available way to improve alertness, but including it would invalidate this whole process, as most energy drinks an concentrates already have a mixture that has caffeine, I would instead like to design one without it and to have a mix that is purpose built to be used aside of a stimulant.

Iso caffeinate

Theobromine

Keep taurine levels below 3 grams per day
The daily doses of vitamin B6 should not be over 50 mg or equivalent, as it can lead to Peripheral neuropathy at high doses.