How well does tea tree oil work to control excess sweat for those with hyperhidrosis?

Unknown. Although recommended on some internet sites the only known uses of tree tea oil are as and antibacterial and antifungal agent on the skin and as a substitute for tea leaves. Well. If you can drink it as a tea, it's probably safe. Hyperhidrosis is due to an imbalance of the autonomic nervous system. Get checked for thyroid & adrenal disease. If negative, try biofeedback or meditation.