To use its medicinal effects, you should use its dry leaves, plucked in July and August. If you cannot find dry leaves, you can also use supplements.
You should use a 2-4ml tincture about three times daily or 1-2 teaspoons of the dried leaves steeped in boiling water for 10-15 minutes to infuse the nutrients in the water.
If applied directly to the skin, it might cause an irritation, so make sure you do a small patch test before use. It should be avoided in the case of pregnancy, glaucoma, enlarged prostate, allergy to ragweed and similar plants, or if you are preparing for a surgery.
Whenever you can, you should turn to natural remedies to treat your health issues, as a safe and effective method to improve your health.