Particularly if you have a relative deficiency of B-Vitamins, you might be able to feel better immediately from higher dose B-Vitamin supplementation, especially B-12

Sometimes a good Calcium/Magnesium supplement can help relax rather quickly.

Some people say the E-mergen-C fizzy drink suppelement provides a fast noticeable benefit (but not all people)

Supplements containing extracts from Ephedra (Ma-Huang), Guarana, Tea, Yerba-Mate, and Kola nut may be felt immediately due to their concentrated alkaloid content.

Otherwise, most supplements available in tablets and capsules don't provide immediate results, especially herbal supplements, due to the very low dosage/recommendations, and a lack of research that went into making the formulation.

If you want to feel quick results from herbs, you must explore the realms of Traditional Chinese Medicine (TCM). In TCM, the dosages of herbs are much higher and in combinations of many herbs, which in many cases enables an effect to be noticeable immediately after taking it. Many of the TCM formulas were developed hundreds of years ago and have stood the test of time.

Anyways thats my 2 cents. Good luck and please post if you have any more questions.

-Ramsemonius.