Corn silk tea is made from corn silk — the long, silky fibers that grow inside the husks of ears of corn.
Corn silk itself is made from the stigma, the yellowish thread-like strands from the female flower of the corn plant. Corn silk tea is a common treatment for bladder infections in traditional Chinese medicine (TCM).
Some people believe many conditions may be treatable with corn silk tea. Scientists have studied a few of these, like heart issues and high blood sugar. So far, scientists haven’t been able to definitively prove such claims. 

Nutrition Information

The fiber in corn silk can improve digestion, but corn silk tea doesn't have as much fiber.
Corn silk tea does not contain any measurable vitamins, minerals, or other nutrients.

Six ounces of corn silk tea contains:
0 calories
0 grams of protein
0 grams of fat
0 grams of carbohydrates
0 grams of fiber
0 grams of sugar

Potential Health Benefits of Corn Silk Tea
A staple of traditional herbal medicine treatments, corn silk is thought to help your health in several ways.
The main proven health advantage seems to be that it provides fiber, though not as much when it's soaked in water for tea and then discarded. 
Improve urinary tract infections (UTIs) - People who practice traditional Native American and Chinese medicine sometimes use corn silk tea to treat urinary tract infections (UTIs).
Act as a diuretic - Scientists have determined that corn silk tea likely has a mild diuretic effect (increased urine production). 
Improve angina - One promising application for corn silk is to help the heart condition angina pectoris. Research says corn silk could make the medicines you take for it work better.

Potential Risks of Corn Silk Tea 
If you have an allergy to corn pollen or corn starch, corn silk may give you:
Rash
Red skin
Itchiness