Does Prozac raise body temperature? (3+ studies)

In this article, we will answer the question, “Does Prozac raise body temperature?”. We will discuss the mechanism behind Prozac’s influence on body temperature, what research has to say in this regard and what to do if you experience such a side effect.

Does Prozac raise body temperature?

Prozac may raise body temperature in some individuals. Hyperthermia or increased body temperature may be reported with the use of antidepressants like Prozac, other selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs).

Prozac (Fluoxetine) is an SSRI approved by the FDA for the treatment of depressive illnesses like major depressive disorder (MDD), obsessive-compulsive disorder (OCD), bulimia nervosa and panic disorder with or without agoraphobia (1).

Body temperature can be affected by several factors like age, stress and even medications Prozac and other antidepressants can cause a change in body temperature. Fluoxetine is known to increase energy expenditure and cause an increase in basal body temperature (2).

How does Prozac raise body temperature?

The potential mechanism behind Prozac’s influence on body temperature is thought to be linked to the increased levels of serotonin in the brain caused by Fluoxetine.

Increased levels of serotonin can cause increased body basal temperature. This increase in body temperature can also be a symptom of the occurrence of serotonin syndrome.

If you feel that the increase in body temperature is due to Prozac, you should immediately contact your healthcare provider, and let them assess the situation to avoid any severe consequences.

What does research suggest?

Various research studies have been published assessing the occurrence of Fluoxetine-induced hyperthermia or increased body temperature.

A research study assessing the effects of Fluoxetine on resting energy expenditure and basal body temperature in normal healthy subjects reported that individuals receiving Fluoxetine 60mg/day reported an increase in basal body temperature when compared to the placebo (2).

A study comparing the efficacy of Fluoxetine and nifedipine for the treatment of Raynaud’s phenomenon stated that individuals receiving Fluoxetine showed reduced severity, timely recovery and better management of symptoms of the cold attacks. This property was attributed to the increased body temperature caused by Fluoxetine use (3).

Another clinical study examined the effects of Fluoxetine and ipsapirone in normal volunteers. The individuals were given both medications during the study. Ipsapirone is known to cause hypothermia, but this response was greatly diminished when individuals were receiving Fluoxetine treatment for almost four weeks (4).

What factors can increase body temperature while on Prozac?

Several factors may cause an increase in body temperature while on Prozac. A few of them are as follows:

Individual physiology

Each individual has a different and unique physiology so their resting body temperatures may vary. Some individuals may be more sensitive to their environment and other factors and may show a rise in body temperature, while others may not.


Elderly individuals have a lower body temperature than adults and adults have a lower temperature than children. With the increase in age, the metabolic rate slows down, causing a decrease in the body temperature as well.


Any stressful situation may cause an increase in body temperature. Stress hormones like cortisol are responsible for this increase. 


Some studies claim that women tend to have a higher body temperature as compared to men. There have been mixed reviews in this regard. However, during ovulation and pregnancy, women do have slightly higher body temperatures.

Time and site of measurement

The time of the day and the site at which temperature is being measured also can play a significant role. Normally the body temperature is lower in the morning and increases during the day. The site of temperature measurement can also affect body temperature readings. Axillary temperature is lower and rectal temperature is higher than the oral temperature.

Dietary factors

Whenever you take a meal, after a few minutes your body temperature will show a slight increase. This is due to the increased metabolic rate, as a result of your meal.

Physical exertion

Exercise and any other kind of physical exertion cause heat production which can cause a rise in body temperature.

Drug side effects

Pharmacological agents like antidepressants and antibiotics can cause an increase in basal body temperature.  

Recreational drugs and smoking

Recreational drugs (like cocaine etc.)and smoking are known to cause an increase in body temperature. If used with Prozac the side effect may become serious.

How to manage a rise in body temperature while on Prozac?

Here are a few tips to help you prevent or manage your symptoms if Prozac is causing a rise in body temperature:

  • Remove any unnecessary layers of clothing and socks
  • Move to a cooler place and do not sit in direct sunlight
  • Use cold compresses or cold water for the face, neck and hands.
  • Drink cold water or electrolyte drinks.
  • Use ice bags under your arms
  • Take a cold shower
  • Wear light-weight clothing
  • Avoid extensive physical activity

Sometimes the rise in body temperature while on Prozac can be a sign of serotonin syndrome. Other symptoms of serotonin syndrome include agitation, headaches, insomnia, confusion, restlessness, tremors, seizures, irregular heartbeat and sweating.

If you have hyperthermia and any of these symptoms it is best advised to consult your healthcare provider immediately so any potentially life-threatening side effect can be ruled out.

To the best of my knowledge and according to research, Prozac may cause a rise in body temperature. The occurrence of hyperthermia may be a symptom of some underlying severe side effects like serotonin syndrome.

If the condition persists and any other symptoms start to arise, it is recommended to seek immediate medical attention. Your healthcare provider will diagnose the underlying cause and modify your treatment plan accordingly.

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The Food and Drug Administration (FDA). HIGHLIGHTS OF PRESCRIBING INFORMATION. PROZAC® (fluoxetine capsules) for oral use. Available from: 


Bross R, Hoffer LJ. Fluoxetine increases resting energy expenditure and basal body temperature in humans. The American journal of clinical nutrition. 1995 May 1;61(5):1020-5.


Coleiro B, Marshall SE, Denton CP, Howell K, Blann A, Welsh KI, Black CM. Treatment of Raynaud’s phenomenon with the selective serotonin reuptake inhibitor fluoxetine. Rheumatology. 2001 Sep 1;40(9):1038-43.


Lerer B, Gelfin Y, Gorfine M, Allolio B, Lesch KP, Newman ME. 5-HT1A receptor function in normal subjects on clinical doses of fluoxetine: blunted temperature and hormone responses to ipsapirone challenge. Neuropsychopharmacology. 1999 Jun 1;20(6):628-39.

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