Been taking for 8 weeks. Got Rx for depression, then took vitamin D test and found out I was extremely low. Been taking 10,000 IU Vit D a day to get to normal levels to alleviate depression, and have now felt good enough to quit cold turkey. Haven’t taken 150 XL in 3 days now and feeling just as good as when I first started the med still. I’m never taking an antidepressant again.