Google+ Icon Facebook Icon Twitter Icon LinkedIn Icon E-Mail Icon language

What is Scalp Cooling?

Scalp cooling is a simple treatment that can prevent hair loss caused by certain chemotherapy drugs.

The use of scalp cooling or ‘cold caps’ is proven to be an effective way of combatting chemotherapy-induced hair loss and can result in a high level of retention or completely preserve the hair. For patients, this means the opportunity to regain some control, maintain their privacy and encourage a positive attitude towards treatment.

Who is Scalp Cooling For?

Scalp cooling (the cold cap) can be used with all solid tumour cancers that are treated with chemotherapy drugs such as taxanes (e.g. docetaxel), alkylating agents (e.g. cyclophosphamide) and anthracyclines/DNA intercalating agents (e.g. doxorubicin). These drugs target rapidly dividing cells and the matrix keratinocytes, which results in hair loss (Paus et al., 2013). This independent decision making tool can help you to get the best estimate of the chance of hair loss in your situation if you enter both your type of chemotherapy and the dosage.

Scalp cooling cannot be used with the following conditions:

  • Haematological malignancies (leukaemia, non Hodgkins and other generalised lymphomas)
  • Cold allergy
  • Cold agglutinins
  • Manifest scalp metastases
  • Imminent bone marrow ablation chemotherapy
  • Imminent skull irradiation
Cap fitting

How Does It Work?

Chemotherapy works by targeting all rapidly dividing cells in the body. Hair is the second fastest dividing cell and this is the reason why many chemotherapy drugs cause alopecia. The hair follicles in the growth phase are attacked, resulting in hair loss approximately 2 weeks after the commencement of the chemotherapy treatment.

The damage that chemotherapy causes to the hair follicle can be alleviated by using scalp cooling, also known as the 'cold cap'. It works by reducing the temperature of the scalp by a few degrees immediately before, during and after the administration of chemotherapy. This in turn reduces the blood flow to hair follicles which may prevent or minimise the hair loss.

Although successful scalp cooling depends on many factors, research and studies have shown that scalp cooling can be effective across a wide range of chemotherapy regimen.

Chemotherapy works by targeting all rapidly dividing cells in the body. Hair is the second fastest dividing cell and this is the reason why many chemotherapy drugs cause alopecia.

The Science

The Paxman Scalp Cooling System has been shown to be very effective in preventing hair loss following a number of different chemotherapy regimes.


Cancer chemotherapy affects rapidly dividing cells and, at any given time, 90% of human hair follicles are in the actively dividing phase. Hair loss frequently occurs due to partial or total atrophy of the hair root bulb, causing constriction of the hair shaft, which then breaks off easily. Cell division is metabolism-driven - this process is decelerated by cooling. Also, a decrease in the metabolic activity of the cells in the hair follicle could cause a more general reduction in the cytotoxicity of chemotherapy drugs localised to the scalp.

Hair Follicles

Scalp cooling causes blood vessel vasoconstriction, which has been shown to reduce blood flow in the scalp to 20-40% of the normal rate, resulting in less chemotherapeutic drug being delivered to the hair follicles. The rate of drug diffusion across a plasma membrane is reduced therefore lower effective drug doses may enter the cells. It is also suggested that reduced biochemical activity due to cooling makes hair follicles less vulnerable to the damage of chemotherapy agents.

Paxman 22ºc

Gregory et al² found that alopecia prevention occurred when scalp temperature was reduced below 22°C and Bulow et al³ demonstrated that a subcutaneous temperature below 22°C corresponds to an epicutaneous temperature of 19°C. Results from these tests indicate that the equipment used in the study reduced scalp temperatures to an optimum constant level for alopecia prevention.

Paxman cold cap

The level of success is determined by how well the scalp temperature is lowered and maintained throughout the treatment period. The Paxman cap has been specifically designed from lightweight silicone to help achieve this, and the equipment has been scientifically tested to prove its effectiveness. The results are shown below.

Scalp Temperature Reduction Graph


  1. Paxman publication: Chemotherapy Induced Hair Loss.
  2. Gregory RP, Cooke T, Middleton J, Buchanan RB, Williams CJ (1982) Prevention of doxorubicin-induced alopecia by scalp hypothermia; relation to degree of cooling. British Medical Journal 284, 1674.
  3. Bulow J, Friberg L, Gaardsting O, Hansen M. Frontal subcutaneous blood flow, and epi and subcutaneous temperatures during scalp cooling in normal man. Scand J Clin Lam Invest 1985, 45, 505-508.

The Safety of Scalp Cooling

Scalp cooling is a well-accepted treatment throughout the world, treating tens of thousands of patients annually. The history of scalp cooling and the cold cap dates back over 30 years, with 56 trials conducted between 1973-2003 and many more to date, providing us with extensive clinical evidence.

The Paxman Scalp Cooling System was introduced in 1997 and was responsible for an increase in the average success rate from 56% to 73%. Today we have more than 2,000 cold cap systems used across 32 countries worldwide, and we continue to improve on the system’s technology and results.

As scalp cooling has been used since the 1970s, the associated side effects of cold caps are well-known.

The safety of scalp cooling

Short to medium-term side effects include:

  • Cold discomfort (during scalp cooling)
  • Headache (during and after scalp cooling)
  • Forehead pain (during scalp cooling) caused by pressure and tightness of the cooling cap
  • Dizziness or light-headedness (during scalp cooling)

The above side effects are temporary and usually only happen during the scalp cooling process. Patients who are known to be, or suspected of being, affected with either of the two following conditions should not use scalp cooling and the cold cap:

Cold urticaria - an allergic reaction to cold temperature, which results in welts on the skin. There is a risk that scalp cooling could elicit a severe anaphylactic reaction, which can be life-threatening.

Cold agglutinin disease - individuals with this condition have high concentrations of circulating antibodies to red blood cells. There is a risk that scalp cooling could cause the low-temperature binding of these antibodies to the patient’s red blood cells, potentially resulting in haemolytic anaemia.

Longer-Term Side Effects

There is only one known potential long-term side effect. Scalp cooling, when used on patients receiving chemotherapy for breast cancer, could potentially lead to an increased rate of scalp metastases. In summary:

  • The evidence all suggests that the risk of getting skin scalp metastasis in women is very low <2.5%.
  • It is extremely rare for skin scalp metastasis to be the first single site of recurrence (0.025%).
  • Nor is there a difference in survival, between women breast cancer patients undergoing chemotherapy who received scalp cooling and those who did not receive scalp cooling.
  • When a patient has scalp metastasis, there are usually other sites of metastatic disease already present.
  • The studies performed to date do not show an increase in scalp metastasis in breast cancer patients receiving scalp cooling to prevent chemotherapy induced alopecia.
  • The data demonstrates the low risk of scalp cooling in an increased incidence of scalp metastasis and that this risk is outweighed by the clinical benefits to the patient of hair preservation.

For an expert statement on the risk of scalp metastases, please contact us.

Download the 2011 Lemieux paper
Breast cancer scalp metastasis as first metastatic site after scalp
cooling: two cases of occurrence after 7- and 9-year follow-up.

Download the 2015 Lemieux paper
No effect of scalp cooling on survival among women
with breast cancer.

Back to top