Botox resistance or fatigue occurs when the injection does not last as long or is ineffective. If the botox is fresh and effective this can be due to circulating antibodies against Botox formed by the body in response to previous injections or changes in the muscle itself over time.
Zytaze (a zinc and phytase prescription medication) given in oral capsule form 2 capsules a day for 4 days (total 10 capsules) prior to Botox injections to patients who responded poorly to Botox injections improved the effect of the Botox injections or how long they last. It is dispensed as 10 per box. This was studied in patients with uncontrolled eyelid twitching (blepharospasm) treated with Botox but should also hold true for Botox administered solely for cosmetic reasons. The mechanism as to why this supplement would be effective or how it works are not known.
Contraindications to botox injections include pregnancy, breast feeding, allergies to components in the botox (human albumin), neuromuscular disorders (myasthenia gravis, Eaton-Lambert syndrome, amyotrophic lateral sclerosis) and use of medications that strengthen the effect of botox (quinine, calcium channel blockers and aminoglycoside antibiotics).