So to make medicine from it,
For the oral intake you have to make tea following this recipe
1. First you have to dry some branches of yarrow flowers in the sun
2. Then you brewed 1 tsp dried yarrow in 1 cup of boiling water.
3. Let it stand for 20 minutes to an hour the most.
4. Then filter it.
5. Drink 1 cup of warm yarrow tea, 15-20 minutes before any meal.
This amazingly helps when you have severe stomach pains (cramps), this helps calm down and heals. That's because Yarrow supports the mucous membranes and has a soothing effect on the digestive systym.