HUMAWORM is very very safe. It can be taken 2-3 times per year. Every 90 days or every 6 months. I have been parasite cleansing for 52 years and I know of other folks who have been cleansing for longer than that and we are all fine.
Doing parasite cleansings closer together than every 90 days can cause resistant parasites - this is why the break is needed. During the waiting period - you can add these "in-between" herbs to your daily food. 1/4 teaspoon each of the following: garlic, onion, sage, thyme, cloves, ginger and cinnamon. You can use the powdered ones found in any store and just use them to spice up your food. They are all anti-parasitical but will not cause resistance.