Skin growths from sun damage (actinic keratosis). Early research suggests that applying a birch bark ointment for 2 months to the affected areas can help clear actinic keratoses.
Conditions of the urinary tract.
Achy joints (rheumatism).
Birch is POSSIBLY SAFE for most adults when taken by mouth or applied to the skin for short periods of time.
Special Precautions & Warnings:
Pregnancy and breast-feeding: There is not enough reliable information about the safety of taking birch if you are pregnant or breast-feeding. Stay on the safe side and avoid use.
Allergy to wild carrot, mugwort, celery, and other spices: Birch pollen might cause allergies in people who are sensitive to wild carrot, mugwort, and celery. This has been called the “celery-carrot-mugwort-spice syndrome.” Birch pollen might also cause allergies in people who are sensitive to certain other plants, including apples, soybeans, hazelnuts, and peanuts.
High blood pressure: There is some concern that birch leaf might increase the amount of salt (sodium) that the body retains, and this can make high blood pressure worse.