Saw Palmetto & The Thyroid

Saw palmetto is sometimes included in products sold as thyroid enhancers. Saw palmetto is a small and slow-growing palm that is native to the southeastern part of the United States. You'll find this herb in formulations including capsules, tablets, extracts, infusions and tea. Always consult a doctor before trying a new herbal formulation, especially if you have a health condition.

Scientific Evidence

No clinical studies demonstrate that saw palmetto will enhance thyroid function, according to "Thyroid Disease," by Harvard Health Publications. The same goes for many other common ingredients in purported thyroid-boosting formulations, including B vitamins, tyrosine, ginger, garlic, valerian, potassium and licorice.

Theories

Saw palmetto sometimes is advocated as an agent to help your thyroid regulate your hormones, sexual glands and organs, which is purported to be helpful for overcoming conditions like decreased sex drive. A change in sex drive is one of the side effects listed for saw palmetto by drugs.com. However, this change may not be on the positive side. A 2009 scientific review published in "Drug Safety" cites decreased libido as one of saw palmetto's side effects. The side effects listed by Harvard Health include potential impotence.

Side Effects

Herbal formulations that include saw palmetto can have impurities, according to Harvard Health. They also can cause side effects aside from affecting sex drive. Saw palmetto can lead to vomiting, nausea, headaches, abdominal pain, urine retention and allergic reactions. Licorice, meanwhile, can cause water retention, raise your blood pressure, lower your blood-potassium levels, cause headaches and lead to lethargy. Always consult a doctor and discuss possible side effects from all of the ingredients in a new supplement before taking it.

Other Uses

While saw palmetto does not appear useful for boosting thyroid health, it is likely effective for treating benign prostatic hyperplasia, or enlarged prostate, according to Medline Plus. In fact, it is approved for treating prostate complaints by Germany's Commission E, that country's regulatory body for herbs. It's also approved by commission E for treating an irritable bladder.