Chemotherapy Drugs That Cause Hair Loss

When people hear the word "chemotherapy," they often think of hair loss as being one of its main side effects. An estimated 65% of patients undergoing classic chemotherapy experience what doctors call alopecia. Not all chemotherapy drugs cause hair loss, though, and the severity of the hair loss or thinning can depend on a variety of factors.

Read on to find out more about why chemo drugs can cause hair loss, which drugs are more likely to cause hair loss, and when hair loss occurs. Your healthcare provider can also provide you with more information specific to your treatment regimen and situation.

Why Chemo Causes Hair Loss

While chemotherapy drugs can be effective in killing cancer cells, they also damage normal cells that divide rapidly. This includes hair follicles (causing hair loss), cells in the digestive tract (causing nausea and vomiting), and cells in bone marrow (resulting in fewer red blood cells, white blood cells, and platelets, causing anemia and fatigue).

Keratinocytes are cells in the hair follicles that help produce hairs. These keratinocytes divide faster than many malignant cancer cells, and they have a good blood supply that delivers chemotherapy agents to them efficiently. Their fast metabolism also puts them under oxidative stress. Chemotherapy drugs can enhance that stress to the point that the cell dies.

Whether or not you develop hair loss, and the severity of hair loss, depends on a number of factors, including:

• The type of chemo drug: Some are more likely to cause hair loss than others.
• Amount (dose) of drug: Higher doses generally have a greater risk of hair loss.
• The combination of drugs (chemotherapy regimen): Receiving a combination of drugs increases the risk.
• How the drugs are given: Intravenous (IV) drugs are more likely to cause hair loss than oral drugs.
• Your individual susceptibility: Some people are more likely to lose hair than others, even with the same doses of the same drugs.

Chemo Drugs That Usually Cause Hair Loss

Chemotherapy medications with the highest risk of causing hair loss (or at least significant hair thinning) in many people include:

• Cytoxan or Neosar (cyclophosphamide)
• Ifex (ifosfamide)
• Adriamycin or Doxil (doxorubicin)
• Vepesid or Toposar (etoposide)
• Camptosar (irinotecan)
• Taxol (paclitaxel)
• Taxotere (docetaxel)
• Ellence (epirubicin),
• Marqibo or Vincasar (vincristine)
• Alocrest or Navelbine (vinorelbine)
• Efudex (fluorouracil)

Chemo Drugs That Sometimes Cause Hair Loss

Some chemotherapy drugs result in only minimal hair loss, though these are often combined with drugs that cause more hair loss. These include:

• Amsidine, m-AMSA (amsacrine)
• Cytosar (cytarabine)
• Blenoxane (bleomycin)
• Busulfex, Myleran (busulfan)
• Efudex, Tolak (5-fluorouracil)
• Oncovin (vincristine)
• Velban, Alkaban-AQ (vinblastine)
• Gleostine, CCNU (lomustine)
• Tepadina (thiotepa)
• Gemzar (gemcitabine)

Timing of Hair Loss

Hair loss often begins around the time of your second chemotherapy infusion, though this varies widely. It may start slowly, but increases rapidly around one month to two months after starting treatment. Some people do not lose all of their hair until they have nearly completed chemotherapy.

Hair re-growth typically begins within three months of concluding chemotherapy. When your hair does grow back, many people find they have what's been coined "chemo curls." If your hair was straight prior to chemotherapy, it will likely become straight again, but this process can take up to several years.

Some women with breast cancer have developed permanent hair loss following a combination of taxanes (such as Taxol or Taxotere) and hormonal therapy, though this is rare. These are not the only treatments implicated.

There have also been a few reported cases of permanent and severe hair loss in women with breast cancer who have received a combination of FEC (fluorouracil/epirubicin/cyclophosphamide) with docetaxel.

Effect of Other Cancer Therapies

The newer targeted therapies for cancer don't usually cause total hair loss like chemotherapy drugs but can result in changes such as thinning of the hair and dryness, as well as changes in texture similar to chemo curls. Some targeted therapies may also affect the pigmentation of hair, often causing the hair to become darker.

Some of the targeted therapies that have been linked with hair changes or hair loss include:

• Cyclin-dependent kinase (CDK) 4/6 inhibitors such as Ibrance (palbociclib), Kisqali (ribociclib), and Verzenio (abemaciclib)
• VEGF inhibitors such as Nexavar (sorafenib)
• BRAF inhibitors such as Zelboraf (vemurafenib) and Tafinlar (dabrafenib)
• BCR/ABL inhibitors such as Tasigna (nilotinib) and Gleevec (imatinib)

Some of the hormonal therapies commonly used for breast cancer have been associated with thinning of the hair for some people. Unlike chemotherapy, people may use hormonal therapies for many months or even years before they notice the changes in their hair. Hormonal therapies more often linked to hair loss include:

• Tamoxifen
• Aromatase inhibitors, more commonly with Arimidex (anastrozole) and Femara (letrozole) than with Aromasin (exemestane)
• Faslodex (fulvestrant)
• Sandostatin (octreotide)

Immunotherapy drugs for cancer, at least checkpoint inhibitors, do not usually cause hair loss, though oftentimes these drugs are used along with chemotherapy. Researchers are looking at ways of harnessing the gene involved in autoimmune alopecia (hair loss such as with alopecia areata) to improve the effectiveness of chemotherapy.

What Else Contributes to Hair Loss

There are a number of non-cancer-related medications that are also associated with hair loss. These might accentuate the effects of chemotherapy drugs if used alongside them.

Some of these include:

• Retinoids (such as Accutane)
• Anti-thyroid medications
• L-Dopa (levodopa)
• Amphetamines
• Non-steroidal anti-inflammatory medications (NSAIDs)
• Antidepressants like tricyclic antidepressants and Wellbutrin (bupropion)

In addition to medications, illness, surgery, or dietary changes (low-protein diets or very low-calorie diets) may lead to hair loss.

Thyroid disease (either hypothyroidism or hyperthyroidism) may cause hair loss and may occur as a result of cancer treatment (such as chemotherapy-induced hyperthyroidism or hypothyroidism, which are very common with immunotherapy).

Summary

Hair loss is a fairly common side effect of various chemotherapy drugs. The severity of hair loss depends on things like the specific drug used, whether drugs are used in combination, the dosage, and how it is given. Other types of cancer therapies can also have effects on hair.

While you may not be able to fully prevent hair loss or thinning, there are things you can do the reduce the risk and plan ahead for potential hair loss. Talk with your treatment team about the drugs you will be on and the risk of hair loss, and develop a plan to cope with it, should it happen.

A Word From Verywell

Many chemotherapy drugs result in hair loss, including those used for breast cancer. Some people choose scalp cooling as a way to reduce hair loss whereas others prefer the comfort of a warm head and planning ahead with a scarf or wig.

The preference is very personal and it's important that you do what is best for you alone. If you are having trouble emotionally with hair loss, seek out a support group or a counselor. This is a normal reaction and you don't have to go through it alone.