Kalydeco and unwanted weight gain???



I'm a 52-year-old female. I was thrilled my gene was approved to start Kalydeco in July 2017, and it's working great to thin and reduce secretions. However, I have a rare gene (1 copy L206W, 1 unidentified) and I'm pancreatic sufficient. I don't struggle to maintain my weight. I'm usually trying to lose a few pounds. I try to eat healthily and exercise regularly. Since starting Kalydeco 4 months ago, I've gained 8 lbs. This is not good news for me. Part of this could be that I take it at 8 a.m. and 8 p.m. and have to eat that fat containing snack at 8 p.m. Is anyone else experiencing unusual weight gain? Advice on healthy fat containing snacks? I eat a lot of peanut butter..... If I don't eat enough fat with it, I get nauseous a little while afterward.



I know how you feel! I've been on Orkambi and tez/iva, so not exactly the same situation, but I too have no need to gain any weight. I just eat it with breakfast and dinner and don't stress too much about it being exactly 12 hours apart. I don't eat an extra meal to take the drug - that might help.


Staff member
DS is on orkambi and usually takes it with breakfast and supper. On weekends when he sleeps in he takes it with breakfast/lunch and then has a snack before bed usually a handful of nuts and a glass of whole milk


New member
I had a similar experience starting Kalydeco - I also have a residual function mutation and am nearly pancreatic sufficient, though not entirely so. I gained about 10-15 pounds in the months after starting Kalydeco (this was more than 3 years ago), but have settled closer to 5 pounds above my starting weight. For me, my metabolism seemed to sort itself out on its own within a year, and I think I probably made gradual changes to my diet over time to accommodate the fact that I didn't need as many calories anymore. I do definitely gain weight more quickly and easily than before, and I do struggle with having to eat snacks to get the doses 12 hours apart - I often wind up needing to eat a spoon of peanut butter or piece of cheese at night when I'm not hungry. One idea would be to save a portion of your dinner to eat at 8pm, so that you're not adding extra food you weren't planning to eat otherwise.


New member
Although I'm not on Kalydeco, I am on Orkambi and have had similar weight gain problems. I did not have a problem gaining weight before starting Orkambi. Once I started taking it, I gained about 15 lbs in the first year. Not a happy camper! So, just recently I changed my eating habits and have lost about 7-8 lbs so far. I have heard of similar stories of people gaining weight after starting these medications.


Super Moderator
I attributed not constantly fighting lung infections to my unwanted weight gain of about six pounds after staring Kalydeco almost four years ago.