IGF1 and acromegaly: In a study of 17 subjects (15 men, 2 postmenopausal women) with acromegaly whose IGF-1 levels remained elevated despite conventional, GH-lowering medical therapy, the addition of tamoxifen reduced IGF-1 levels by an average of 90 ng/mL and normalized plasma IGF-1 in 47% of subjects [10].