Letrozole and Headaches: What Users Say

• Lov...
• Taken for 2 to 5 years
• October 9, 2013

Letrozole for Breast Cancer "After a lumpectomy for stage 1 breast cancer, I was prescribed two other aromatase inhibitors prior to Femara. I had occasional head pain in one spot from all of them. I also had trigger finger and terrible knee pain from Arimidex. My doctor then put me on brand name Femara and the joint pain, head pain, and trigger finger all went away. What is bothering me now is the hair loss (can see my scalp!), memory loss-constantly groping for words. Sometimes I do feel like I'm 'foggy' but mostly I just can't remember words. I feel it is getting worse as time goes on and I do not understand why others report the same but there is no mention of this in the patient information leaflet."

• Sja...
• Taken for less than 1 month
• March 2, 2021

For Female Infertility "I was diagnosed with PCOS 3 months ago after going to a fertility clinic, although I thought I had it when I was admitted to a hospital 4 years ago with a cyst that popped and made me very sick! The doctors just shrugged it off, and this happened twice! I’ve just started taking letrozole 5mg/day 2-6 and just received my smiley face!! Side effects were bad headaches that I couldn’t shake off and hot sweats. Later on, before I ovulated, I felt like my ovaries were going to pop (googled this thinking it was going to happen), so fingers crossed my next cycle will be the one, and we will get our first BFP! For those TTC, I send lots of baby dust your way, and for those who are already there, I wish you a happy, wonderful pregnancy."

• tin...
• Taken for 6 months to 1 year
• April 29, 2023

Letrozole for Breast Cancer "Awful! I've been on Femara for about 8 months. And since I started, I seem to have every single side effect. My joint and muscle pain is excruciating. In no particular order, I suffer with body pain (fingers, hands, shoulders, chest, back, sides, hips, legs, feet - basically everything head to toe). Plus, weight loss, hot flashes, headaches, dizziness, thinning of hair, dry mouth, high BP, night sweats. Even my scalp is tender. Chest pain that radiates to upper arms, shortness of breath, overall depression. Chills, insomnia, intestinal pain - sharp pains, plus dull aching. Constant feelings of nausea, diarrhea, constipation. I'm afraid to eat but also have little appetite. Brain fog, shortness of breath. Feeling that I am just going to die. Sitting up in pain all night. I hurt everywhere - too sick to move; too sick to cry. Feels like I am going to have a heart attack. Can’t lie down, can’t stand up. Full body chills, hands shaking. Haven't slept through the night in months."

• Sho...
• September 21, 2016

Letrozole for Breast Cancer "I've been taking letrozole (Femara) for 9 months, after a right-side mastectomy for stage IIA breast cancer. I'm ER & PR positive. No radiation or chemo. I'm 58 & this is the only drug I take, besides vitamins. The first 6 weeks I had trouble sleeping, occasional dizziness, some joint pain, & mild headaches. Around 4 months in, I started losing hair. I'd guess approximately 25% of my hair has fallen out. Besides the hair loss, I have dry eyes, genitals, & skin. There's some stiffness & joint pain in my hips. These side effects are tolerable, especially knowing that the drug is preventing a cancer recurrence. None of these side effects are enough for me to stop taking letrozole!"

• 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."

• Sex...
• Taken for less than 1 month
• February 25, 2020

For Breast Cancer "I have been using this drug letrozole for almost a month. I have chills so bad I can't warm up. Headaches, can't sleep, and have diarrhea and dizziness. I am also having muscle spasms and pain in my bones. Help."

• 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."

• Anonymous
• Taken for 1 to 6 months
• February 15, 2022

For Female Infertility "I have suffered with PCOS for years and have never been pregnant before. My partner and I have had unprotected sex for about 5 years. He has low sperm morphology. We were told to have IVF/ICSI straight away, but then a different fertility nurse told me to try letrozole just in case. I was certain it wouldn’t work. I was prescribed 2.5 mg days 2-6. The first month it didn’t work, despite us having timed sex and having ovulation confirmed by ultrasound. No trigger shot or blood tests. On the second month (this month!), it worked! I still can’t believe it. Had blazing positive tests on 10 dpo. One thing I would say is that on both months, my boobs were VERY sore, so maybe this is a side effect of letrozole instead of pregnancy. I also had mild headaches on both rounds. Aside from this, letrozole has been absolutely fine, and I haven’t had any serious side effects, I’d have happily continued taking it if I didn’t get pregnant. Don’t lose hope!!! 10/10 from me."

• Tul...
• Taken for less than 1 month
• February 6, 2020

For Breast Cancer "I had 2 tumors removed, 2 operations, radiotherapy, and medication letrozole. 28 days in taking letrozole, headaches, joint pain, muscle aches, hot flushes, and terrible mood swings. Hope to heaven this is not to be with me every day as I'm not sure how I can keep working."

• Ray...
• April 3, 2021

For Female Infertility "I have been trying to conceive for two years now. Last month, my doc placed me on letrozole 2.5 mg. Just started mine, though, today makes it day 6, ending tomorrow for my first cycle. Been having terrible headaches since morning, I guess that's one of the effects. I hope and pray I test positive this month. Baby dust to you all."

• Ray...
• April 3, 2021

For Female Infertility "I have been trying to conceive for two years now. Last month, my doc placed me on letrozole 2.5 mg. Just started mine, though, today makes it day 6, ending tomorrow for my first cycle. Been having terrible headaches since morning, I guess that's one of the effects. I hope and pray I test positive this month. Baby dust to you all."

• can...
• Taken for 1 to 2 years
• February 27, 2018

For Breast Cancer, Adjuvant "In 2015, I was diagnosed with stage 2A right breast cancer. I had a mastectomy and reconstruction, as well as a full hysterectomy. This is my second year on Letrozole (scheduled for 5), and my symptoms have just started. Mild headaches, back and neck pain, muscle aches, weight gain, and hair loss. The latest is nausea, which I hate! I have high blood pressure, and it has been going up alarmingly. That's really the main concern that I have since heart disease and strokes run in my family. For the first year, I had no side effects, but now it seems like every one of them is converging at the same time. I'm wondering what I'll experience next, but I've decided to remain on the medication and will try to mitigate the symptoms as best I can. I'm 48 and have had a wonderful life, but I'm living for my family, and especially my new grandchild. So, I'll suffer, but it's worth it to stick around for as long as I can."

• Ely...
• Taken for 6 months to 1 year
• December 17, 2016

For Breast Cancer "Surgery for ER Stage 2 in right breast. Started letrozole before radiation. Had a lumpectomy and one sentinel node out below the armpit. So next, a sore, red, swollen breast. My GP put me on huge doses of antibiotics. Didn't work. Surgeon then told me it was lymphedema. Gave me dexamethasone (appalling side effects). Had to stop it, and it took a month to settle the problems down, settled infection but not lymph blockage. Off to a lymphedema nurse, learning exercises and massage. Acutely tired. Loss of interest/drive. Headaches, mind blurriness, and bad recall. Eyes also blurry. Aching everywhere began and grew so badly could barely move. Taken off Femara. Three weeks later still ache badly. Back soon to decide what to do. Hard decisions..."

• KTa...
• Taken for less than 1 month
• April 19, 2018

For Female Infertility "I took two 2.5 mg pills at night for cycle days 3-7. I had no side effects the first 3 days. Then, the 4th day, my right knee started hurting when going up and down stairs. It hurts every once in a while, so I thought it was no big deal. Well, now it is unbearable. I can hardly move my knee without pain. It hurts to drive, cross my legs, walk, etc. I have been off this pill for 2 full days, and it is getting worse, not better. Then, this morning, I had a severe headache. Quite possibly the worst one I have ever had. It took all I could do to get out of bed. I also had severe joint pain in my shoulders. I have never had that. I am praying that the pain subsides, or I may not be able to drive/work. The only benefit is that my insurance company (Anthem) covered this pill 100% because it is labeled as breast cancer preventative. This is nice, as fertility drugs are not typically covered."

• yel...
• Taken for 1 to 6 months
• December 8, 2019

For Female Infertility "I had taken one round of letrozole last month, 2.5 x 5 days, now I'm on 5 mg x 5 days. The side effects include swollen hands and feet, along with headache and nausea. Wondering if anyone has ever taken a higher dosage and if the side effects are similar."

• Anonymous
• July 27, 2022

For Female Infertility "I was prescribed letrozole 5 mg x 5 days on cycle day 3-7. I began feeling ill on the 3rd day of taking the medication. I had really bad muscle/bone/joint aches, headaches, hot flashes, abdominal pains, lack of appetite, dry mouth, cough, dizziness, nausea, and fever. I called the pharmacy to ask about side effects and was told to complete the 5-day regimen since I only had 1 dose left. No sinus symptoms or sore throat, but I went to get COVID and flu tested and was negative. Blood work showed elevated liver enzymes. No signs of infection. Still having headaches and now stomatitis. Every day I am feeling a little better. I read side effects can take 7-10 days to subside. I am on day 6 and still don't feel like myself. Praying I do end up pregnant after experiencing almost every side effect possible. I did have an increase in follicle sizes from the medication."

• 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."

• DKC...
• March 3, 2023

For Female Infertility "So at 40, I ended up pregnant after my husband had a vasectomy! Yes, we tested it, and it was clean... then 8 months later I find out I'm 3 months pregnant! Thinking I was just missing periods due to age... Yes, he is fertile again! We have our miracle baby boy now! So we decided to try again for another since we completely started over with the kids. This time I've had three chemical pregnancies in 7 months! I am 42 now and can obviously get pregnant. The doctor put me on letrozole 2.5 on days 3-7 to help move things along. Now just moved to 5 mg days 3-7, but I will warn you... it gives me horrible headaches! Also, I just feel sick and have anxiety due to the symptoms it gives me. The worst is days 3-5 on the medication. Praying for a pregnancy to stick! Also taking progesterone post-ovulation now to help. Baby dust to all!"

• Anonymous
• Taken for 1 to 6 months
• September 5, 2021

For Female Infertility "I have had PCOS since I was a teenager. I got pregnant unexpectedly with my husband in 2017, we have a 4-year-old son. We have been trying to conceive since our son was born. We found out we were pregnant with baby #2 on Christmas Eve. We were so excited, but three days later, we had a miscarriage back in 2019. We have still been trying since. I have lost 56 pounds, have cut sugar and carbs out of my diet, I am very active, and my periods have since become regular. I have three tracking apps to track everything. The last year, from September 2020 to now, September 2021, still no babies. We started letrozole 2.5 on the third day of my period, 5 pills, one each day. This is our third round, no luck still. I have had horrible night sweats and headaches and no energy when I take the medication. My husband and I have had sex every day from the last day of my period to the start of my next, and still no luck. I don't understand, we have one more try!"