Lenalidomide (Revlimid) is one of the main medicines for multiple myeloma, a cancer of the plasma cells in the bone marrow. Many people take it for a long time, either as part of their main treatment or as maintenance after a stem cell transplant. Because it can cause serious birth defects, it also comes with some of the strictest safety rules of any tablet. This guide explains what to expect.
Where lenalidomide fits
In the US, lenalidomide is licensed for multiple myeloma together with the steroid dexamethasone, and on its own as maintenance after a stem cell transplant. It is also used for some other blood conditions, including certain types of myelodysplastic syndrome and lymphoma1.
Lenalidomide works in several ways. It interferes with the signals cancer cells use to grow, helps the immune system attack cancer cells, and blocks the growth of new blood vessels that cancers need2. It is not a traditional chemotherapy. See our guide is it chemotherapy?
Doses and schedules
| Use | Usual starting dose | How long |
|---|---|---|
| Main treatment, with dexamethasone | 25 mg once a day on days 1 to 21 of each 28-day cycle1 | Until the myeloma progresses or side effects become too much1 |
| Maintenance after a stem cell transplant | 10 mg once a day, every day of each 28-day cycle; may increase to 15 mg after 3 cycles1 | Until the myeloma progresses or side effects become too much1 |
Doses are lower for people with kidney problems, and are often adjusted for side effects1. Swallow the capsules whole with water, with or without food, and do not open, break or chew them1.
Missed dose: you can take it up to 12 hours after your usual time. If more than 12 hours have passed, skip that day’s dose and take the next one at the usual time the next day. Never take two doses to make up1.
People who may have a stem cell transplant need their stem cells collected within the first 4 cycles of a lenalidomide treatment, because longer treatment can reduce how many cells can be collected1.
Side effects
The most common side effects in myeloma include diarrhoea, tiredness, anaemia, constipation, low white blood cells, swollen ankles, trouble sleeping, muscle cramps, stomach and back pain, nausea, fever, colds and chest infections, cough, rash, breathlessness, dizziness, poor appetite, low platelets and tremor1.
Blood counts are checked every week for the first 2 cycles, on days 1 and 15 of the third cycle, and every 4 weeks after that1. Report signs of infection, such as a fever, and unusual bruising or bleeding.
Blood clots: why you may be given a blood thinner
Lenalidomide with dexamethasone raises the risk of blood clots in the legs and lungs, and of heart attack and stroke1. The label recommends medicine to prevent clots, chosen according to each person’s risk. In one large trial, all patients had clot prevention, most often aspirin1.
Get medical help straight away if you have breathlessness, chest pain, or swelling in an arm or leg1.
Pregnancy prevention: strict rules
Lenalidomide is related to thalidomide, which causes severe birth defects, and lenalidomide caused limb defects in animal studies. It must not be used in pregnancy1. The US label sets these rules:
- Women who could become pregnant need 2 negative pregnancy tests before starting, and must use 2 forms of contraception, or not have heterosexual sex at all, during treatment and for 4 weeks after1.
- Men must always use a latex or synthetic condom during any sexual contact with a woman who could become pregnant, during treatment and for 4 weeks after, even if they have had a vasectomy, because lenalidomide is found in semen. Men must not donate sperm during this time1.
- Everyone taking it must not donate blood during treatment or for 4 weeks after1.
In the US, lenalidomide is only available through a restricted safety programme (the Lenalidomide REMS programme) that prescribers, pharmacies and patients must follow1. Follow the pregnancy prevention rules of your own prescriber and country exactly.
Second cancers: how the risk is weighed
In myeloma trials, people taking lenalidomide had more second cancers, including the blood disorders AML and MDS, as well as some solid cancers1. Your specialist weighs this risk against the benefit of treatment and will keep checking for new cancers. Ask about it if it worries you.
Other warnings
Lenalidomide can also cause liver problems, severe skin reactions and tumour lysis syndrome (a problem caused by the rapid breakdown of cancer cells)1. Tell your team about yellowing of the skin or eyes, a widespread rash or blistering, or reduced urine.
Lenalidomide vs thalidomide vs pomalidomide
| Thalidomide | Lenalidomide | Pomalidomide | |
|---|---|---|---|
| Main use in myeloma (US) | Newly diagnosed myeloma, with dexamethasone3 | Main treatment with dexamethasone, and maintenance after transplant1 | After at least two earlier treatments, including lenalidomide4 |
All three are related medicines, and pomalidomide is used when myeloma has grown despite lenalidomide and another type of myeloma medicine4. See our guide to when a cancer medicine stops working and to taking cancer tablets at home.
Generic versions and cost
Our generic Revlimid page and our guide to what Revlimid costs explain the options. We stock Lenalid 10 mg capsules, as well as thalidomide (Thalix 100 mg) and pomalidomide (Pomalid 4 mg). See our thalidomide and pomalidomide pages and our multiple myeloma medicines. All need a prescription, and the pregnancy prevention rules apply whichever brand you take.
Frequently asked questions
How long can you take lenalidomide?
Often for a long time. As maintenance after a stem cell transplant, and as part of main treatment, it is usually continued until the myeloma progresses or the side effects become too much.
Does lenalidomide cause hair loss?
Hair loss is not listed among the most common side effects of lenalidomide in the US label. Tell your team about any side effect that bothers you.
Is lenalidomide chemotherapy?
No. It works in several ways, including helping the immune system attack cancer cells and blocking the blood supply cancers need. It is not a traditional chemotherapy.
Why do I need to take aspirin with lenalidomide?
Lenalidomide, especially with dexamethasone, raises the risk of blood clots. A blood thinner such as aspirin, or a stronger anticoagulant, is chosen according to your own risk.
Can my partner get pregnant while I take lenalidomide?
Pregnancy must be avoided. Men must use condoms during and for 4 weeks after treatment, even after a vasectomy, and women who could become pregnant must use 2 forms of contraception.
Sources & references
- US National Library of Medicine, DailyMed. Revlimid (lenalidomide) prescribing information.
- Cancer Research UK. Lenalidomide (Revlimid). Last reviewed 13 October 2025.
- US National Library of Medicine, DailyMed. Thalomid (thalidomide) prescribing information.
- US National Library of Medicine, DailyMed. Pomalyst (pomalidomide) prescribing information.
Related reading
This content is for informational purposes only and is not medical advice. Lenalidomide must only be taken under a specialist’s care and with the required pregnancy prevention measures. Used as prescribed by a licensed medical professional.
Jacob T. is a licensed clinical pharmacist with 18 years of experience. He holds a B.Pharm and M.Pharm from Dr. M.G.R. Medical University. At OnlineMeds, he reviews medicine and health content to help ensure it is accurate, evidence-based, and easy to understand.