Letrozole and Fatigue: What Users Say

• Anonymous
• Taken for 1 to 6 months
• July 29, 2020

For Female Infertility "I had been trying to get pregnant for 2 years. Did a few rounds of Clomid without results. Got diagnosed with PCOS. Did one round of Letrozole 5 mg and trigger shot without results. For round two, my doc upped it to 7.5 mg plus trigger shot, and it was successful! Daughter is now 1 year old, and we are trying again starting at 7.5 mg. Experiencing depression, fatigue, and intense dreams. Baby dust to all!"

• cau...
• August 30, 2013

Letrozole for Breast Cancer, Adjuvant "I had stage 3 breast cancer, have been through chemo, radiation, and have been on Femara for 4 months. I started on Aromasin but had terrible joint and muscle pain, so my oncologist changed me to Femara. My joints and muscles feel better, but I am so tired that even my oncologist tells me I look worn out. I will live with the fatigue as I know this medicine works. I am 58, and I can no longer do what I did less than a year ago. I ride a bike 40 minutes a day, I eat healthy, but I just have no vitality. I miss my old self."

• dog...
• Taken for 2 to 5 years
• July 19, 2014

Letrozole for Breast Cancer, Adjuvant "I was diagnosed in 2009, had lumpectomy, chemo, radiation. Managed to continue working through it all. Then took tamoxifen for 2 1/2 years... had horrible muscle cramping and hot flashes, switched to letrozole after determining I was postmenopausal. The major muscle cramps lessened considerably, as did the hot flashes. I took this for 2 1/2 years, just stopping 3 weeks ago. I have muscle, joint, bone achiness 24/7, no energy, tired always, feel like I'm in a fog, tinnitus, heartburn, slow metabolism with weight gain. How long will it take to reverse all of these side effects now that I no longer take it? I even quit taking ibuprofen because it doesn't do anything for the pains. I am now 2 months from being 50 years old."

• gre...
• November 2, 2015

Letrozole for Breast Cancer "Had lump removed April 2014, 15 treatments of Radiotherapy then Letrozole. The doctor only warned about making my already present aches pains worse but felt this was the best for my age, now 70. I went out with my daughter on Friday and felt I had to drag myself around, so wiped out. I feel the need to sit down all the time. Going upstairs to bed, by the time I get to the top of the stairs, I'm sweating, very hot, and feel like I'm running out of air, I have to sit down on the toilet while I cool down. During the day, I constantly fall asleep. I feel this is a poor life with no energy to do anything. I wake up in the morning with a headache and sometimes feel sick."

• CHA...
• Taken for 6 months to 1 year
• February 26, 2014

For Breast Cancer "Was on Arimidex for one year but was changed to Letrozole because I couldn't walk due to burning sensation. Side effects after treatment have been: bone weakening, fatigue, insomnia, night sweats, weight gain (40 lb), dry hair, feel older than 71, redness in my face, high blood pressure, neuropathy, burping, stiffness after sitting, memory loss, joint pain...but I am happy to be alive. I try not to complain because I want my husband to be happy."

• Can...
• Taken for 1 to 6 months
• August 18, 2015

Letrozole for Breast Cancer "Diagnosed May 2014 with Stage 3 Breast cancer after chemo, removal of the tumor & lymph nodes, radiation. I started Femara, been on it almost 6 months and I have daily joint & muscle pain, fatigue, hot flashes, and most of all weight gain. I'm really trying to eat healthy and exercise, but working a full-time job, it's a tough routine to keep up with every day (55 and post-menopausal). But hey, I'm still here and hopeful the medication does a good job of keeping the cancer at bay. Doing my best with the symptoms."

• Hai...
• Taken for less than 1 month
• November 23, 2019

For Breast Cancer "I didn't take this medicine, but my grandma did. I lived with her and have seen how this medicine affected her. She started letrozole on a Friday, and by Thursday she was in ICU. Before she was hospitalized, this medicine caused her extreme discomfort. She was in bed all day, every day. She has fatigue, weakness (so bad she couldn't sit up by herself), hot flashes, throwing up, joint and muscle pain, fever, and dizziness. Thursday, she got so bad to the point she was struggling to breathe. In the hospital, they discovered a blood clot, which is a side effect. Two weeks before she started this medicine, she went to the doctor and had an MRI and a CAT scan. There were no clots. This medicine made her miserable. Now she is in ICU, and we were told she probably will not be coming home. She was fine until she started this medication."

• joa...
• Taken for 6 months to 1 year
• November 13, 2018

For Breast Cancer "I started taking letrozole in June. Side effects started almost immediately: fatigue, hot flashes, joint and muscle aches, and hair thinning. I have cut my hair very short to hopefully make the thinning less noticeable. I just realized that I cut my hair 5-6 weeks ago, and it does not seem to be growing at all. Has anyone else noticed this side effect? I would recommend yoga and acupuncture to help with the side effects. Without them, I would not be able to tolerate this medicine! Good luck to you all who are taking this drug!"

• Ela...
• Taken for 6 months to 1 year
• August 11, 2018

For Breast Cancer "Diagnosed with breast cancer 2 years ago. Took anastrozole, which had side effects: fatigue, memory loss, weight gain. Doctor changed me to letrozole. On it for 7 months, I have the worst joint, muscle, and body aches. There are some days I can’t stand up on my legs. My arms, shoulders, and back hurt constantly, fatigue. 7 months ago, I used to walk 2 miles a day. Today I can’t even get on a treadmill for 5 minutes. I have been taken off letrozole, it’s only been a week."

• Anonymous
• November 11, 2012

For Breast Cancer "I am 40 years old and I have been taking Letrozole for about a year. I found a lump shortly after my son was born 5 years ago. I had chemo, radiation, and was put on tamoxifen. I had a recurrence in the lymph node in Dec of 2011, and the oncologist took me off tamoxifen and put me on letrozole. I am suffering from joint pain, memory loss, very fatigued all the time, depression, hot flashes. I do very little for myself since my children are only 9 and 5 years old. I feel I need to take care of them first before I can do anything for myself. I am hoping the letrozole will give me more hope than tamoxifen. I'm preventing a recurrence. I need to be around a lot longer for my beautiful children."

• Mar...
• April 28, 2015

For Breast Cancer "I hope that it is keeping me from having cancer with all the problems that it is causing. I had stage 2 grade 2B breast cancer and had a mastectomy followed by 6 months of chemo and 6 weeks of daily radiation. I really didn't have that many side effects from chemo and radiation. But being on the letrozole has been a pain. The fatigue is getting to me. I might as well go into hibernation for 5 years. I sleep all the time. It is very hard to focus on my job where I am a manager. I have a lot of joint pain and I am trying glucosamine juice. Someone else told me about loins juice. Does anyone have any ideas on what to do about the fatigue? I take the pill at night, but I cannot get out of bed in the morning."

• sic...
• Taken for 2 to 5 years
• July 27, 2014

For Breast Cancer, Adjuvant "I was so pleased to read all of the reviews about Letrozole. Now I know that I'm not alone. Hot flashes worse than menopause. Always off balance. Won't do stairs without a railing or holding on to a person anymore after quite a few falls. Don't get dizzy, but never know when a stumble or fall is coming. Very dry mouth (other meds also cause dry mouth/thirst). This is extremely hard to deal with as chemo put my kidneys in failure and on dialysis I am limited to 1.5 liters of liquid a day. Headaches, bone pain, fatigued constantly, muscle pain especially in legs, lack of appetite, foods don't taste the same. Ran out about a week ago, starting to come out of the fog! Feel like I'm 100, not 57, sigh."

• lyn...
• Taken for 1 to 6 months
• May 20, 2015

For Breast Cancer "After stage 2 breast cancer/unilateral mastectomy, I took tamoxifen for 2 years, then switched to Femara about 4 months ago. My oncologist said this was largely because Femara is kinder to my kidneys. I truly hope the Femara is doing its job, because my fingers are stiff and swollen, and they hurt when I bend them. I now have 2 - 3 trigger fingers, depending on temperature and time of day, and I truly understand what a reviewer called 'Walter Brennan walk'! Stiff legs after sitting for as little as 5 minutes, and as an artist, pianist, and admin, this is definitely a quality of life issue for me. I am going to speak with my doctor again - he agreed that this was a side effect, but it's getting worse quickly, along with slight weight gain and low energy levels."

• Lis...
• Taken for 1 to 2 years
• April 16, 2018

For Breast Cancer, Metastatic "I had breast cancer 9 yrs ago, stage 1. I had 4 mo's chemo, 6 weeks radiation. Then, a 1 1/2 yr. ago it came back, stage 4, and it metastasized to both my lungs. Now, I’ve been on Letrozole for 1 1/2 yrs, and a few of my tumors shrunk and have stabilized the others. I’ve had some side effects, which are brain fog, night sweats, fatigue, and dryness. It’s been very tolerable. I call Letrozole my miracle pill! Good luck to you all! ❤️"

• Kim...
• Taken for 1 to 2 years
• May 20, 2018

For Breast Cancer "I have been on letrozole for 13 months, which I began after a lumpectomy of my left breast, followed by four months of chemo and four weeks of radiation. For many months, my only noticeable side effect was fatigue. I always took it at night, so this was not too much of an issue. Within the last few months, I’ve been experiencing increasingly more painful joint and muscle pain in my shoulders and arms. Sometimes ibuprofen seems to ease the pain, but not always. I’m hoping it doesn’t get worse, for it is not easy to ignore. And yes, I’ve had weight gain also... the 20 lb seems to be the magic number, however, being menopausal, this was occurring with me anyway. I have a very active job with a lot of lifting and walking, but the weight gain won’t budge."

• Lxc...
• Taken for 1 to 2 years
• January 2, 2018

For Breast Cancer, Adjuvant "Horrible bone pain - all over the body, finger bone pains, sweating, depression, extreme fatigue. Unable to do anything. Pain too extreme. Fatigue horrendous. Stopped on 12/28/17 after 18 months of hell."

• Fif...
• April 28, 2016

For Breast Cancer "Diagnosed with breast cancer, Nov 2013, double mastectomy, chemo, radiation therapy, oophorectomy. Side effects: leg cramps, disturbed sleep, palpitations, hot flushes, muscle, joint, and back pain, hair thinning, nausea, fatigue, increased appetite, breathlessness."

• Yoj...
• January 4, 2018

For Breast Cancer "Had chemo every other week for 4 treatments, surgery, another 4 sessions of chemo, then radiation every weekday for 33 sessions. Neulasta shots day after chemo, that was so horrible, excruciating body aches. I've been on letrozole for 8 months. Side effects have been muscle aches, fatigue, some nausea, dry mouth, trigger thumb, hot flashes, weight gain, blurry vision, insomnia, occasional decrease in appetite, neuropathy mostly in my feet (maybe from the chemo?). Is that enough? My doctor wants to give me a 3-4 week break, but I'm scared to stop. I can live with these side effects if it keeps me from a recurrence. I am feeling better, not quite as tired or nauseated. I'm glad I'm not the only one with the symptoms."

• Anonymous
• October 1, 2017

For Breast Cancer, Metastatic "It was toxic to me. Severe joint pain, insomnia, osteoporosis, increased cholesterol count, and spinal stenosis. I also lacked libido and energy. It is worth the small chance of recurrence. I am still in pain, and I have been off of it since the end of April. It has impacted my life enormously; I regret taking it."

• Anonymous
• Taken for 2 to 5 years
• March 13, 2021

Letrozole for Breast Cancer, Adjuvant "Bone pain, trigger fingers, joint pain, hip pain, wrists/thumbs repeated tendonitis, low energy. From anastrozole to letrozole, issues persist, worse over time. Still on it, but had to stop working. Managing to stay on as benefit outweighs risk."

• Old...
• Taken for 1 to 6 months
• March 10, 2023

For Breast Cancer "It was okay for the first month. I had hot flushes that subsided after a few weeks. Then the pain in my joints, lack of energy, and low mood kicked in. I didn't feel like doing anything, which was just as well, as I was in a lot of pain just walking around the house. My hips, knees, and lower back were the worst. They hurt all the time - even when I lay down to sleep. After five months of suffering on Letrozole, I was recently told I am pre-diabetic. I have just stopped taking the drug and have a phone appointment to discuss with my GP."

• Ral...
• Taken for 10 years or more
• June 14, 2024

For Breast Cancer, Metastatic "Metastatic breast cancer - L5 vertebra metastases diagnosed in October 2008. I started Femara in November 2008 and took one daily until July 2023 when I switched to generic: Letrozole. As long as I took Femara, the adverse effects were tolerable: at first there were hot flashes (about 2 years) with fatigue, hair thinning. Since last year, since I have been taking the generic Letrozole, I have had joint pain, burning sensation in the soles, bilateral carpal tunnel syndrome, sensitive peripheral neuropathy. Since March 2024, I have developed a sensation of facial paresthesias (chin/lower and upper lip), numbness and tingling in the skin of my arms and legs bilaterally. However, almost 16 years on from my initial diagnosis I have no signs of breast cancer recurrence so I will continue with Letrozole"

• Ano...
• Taken for less than 1 month
• November 12, 2019

For Female Infertility "I just started taking letrozole for help getting pregnant. I'm on 7.5 mg on Day 3 and 2.5 mg on Day 4. I had to decrease the dose due to the side effects. I have joint, muscle, and bone pain, tender breasts, fatigue, and headache. It's a good thing that I am not working at this time. I am wondering whether or not to continue the course."

• Ble...
• Taken for 2 to 5 years
• July 12, 2022

For Breast Cancer "I have tried other related anti-hormone drugs to help on my breast cancer journey. The side effects of Letrozole for my body were the least compared to any others they tried me on over months. There is less bone pain, nausea, sweating, moodiness, fatigue on Letrozole than the others. Everyone's body is different and reacts differently. My personal choice is Letrozole. I highly recommend taking it every night at the same time. I only stopped it a week before my PET scans to help reduce inflammation for the scan. Then I go right back on it. Usually, this week I stop this medication, it doesn't fully leave your body, so it is no issue with the side effects when you continue it."

• But...
• Taken for 1 to 2 years
• March 21, 2021

For Breast Cancer, Adjuvant "I have been on letrozole for over a year now with minimal side effects. I do have bone pain and some fatigue. However, I wanted to share that the only thing I did differently before I was diagnosed with estrogen/progesterone-driven breast cancer is I started taking collagen supplements. I noticed in the comments that someone is taking this along with letrozole, and I wanted to share an article from a breast cancer survivor turned cancer coach. I have done exhaustive research myself, and I have concluded that collagen supplementation is a danger to us survivors, especially Type I. The only collagen that inhibits tumor growth is Type III, but I am finding it impossible to find a supplement that is only Type III, most are combined with other types, especially common is Type I coupled with Type III."