It may be the other way around, your low thyroid is causing your parasites because low thyroid makes your digestion slow/constipation leading to candida and parasites from undigested and fermented food backed up in the colon. I did cleansing and detoxing forever and just felt sicker and sicker. It was too hard on my throid and adrenals to do all of those cleanses and so I started working on my thyroid. My digestion isn't 100% but I am free from many of the candida symptoms I once experienced. I take a product from apex entergentics to boost my thyroid and am feeling wonderful and back at the gym. I am also on an antidepressant. The product I take for my thyroid is called K-9 CNV from apex entergentics and I also take an adrenal supplement and lots of b vitamins and vitamin c.