You will lose weight on a parasite cleanse. After the cleanse, if parasites were a problem you might gain it back.
I've tried parasite cleanses to gain weight and it was a total disaster. I lost almost 10 lbs, since they are very purgative.
Why don't you look into the following:
- Adrenal fatigue / Addison's disease
- thyroid problems
- Ayurveda vata dosha

I have been to many alternative doctors, western doctors and also studied Acupuncture and herbs. In all of that, the only thing that I can say for sure is that you should not try to self-diagnose.

Exercise stimulates the release of growth hormone, which is obviously helpful in gaining weight. You won't end up looking like a man -- just do moderate weight resistance training, but never to exhaustion. It will be helpful.

Good Luck,
Keep us posted!

I am on my last week of humaworm cleanse and I haven't lost any weight. I did get a little constipated this last week, but my energy was alot better. I usually have low energy, so it must have taken a load off somehow. Maybe the parasites were zapping my energy. My husband and I both are on it and I've been on others with no results. We will continue to use humaworm at least a couple of times a year. I am very thin also and do not like using products that may cause weight loss.