Amitriptyline and Weight Gain

675440085Amitriptyline is a tricyclic antidepressant used as a treatment for depression, anxiety disorders and sometimes migraines. There are some conditions where the Amitriptyline is used “off-label” for certain conditions such as attention deficit hyperactivity disorder (ADHD), eating disorders and post-herpetic neuralgia. It has a mechanism of preventing the serotonin entrance inside the cell, increasing its concentration, therefore reducing the depression by elevating the mood. Serotonin is known by its effects and it is called “the hormone of happiness”. Other accompanied effects may have to do with affecting norepinephrine which is a neurotransmitter in the nervous system. This drug is commonly prescribed to mentioned conditions as a drug of the first choice among other newer medications or selective serotonin reuptake inhibitors (SSRIs). It was approved by FDA in 1983. Amitriptyline is very popular and widespread with its benefits, although some of the patients experienced weight gain as a side effect.

Amitriptyline And Weight Gain

There are many studies which showed Amitriptyline causing weight gain in patients on therapy for depression. A study was conducted among 73 patients treated with 4 different medications: amitriptyline, nortriptyline, desipramine, or zimelidine. They observed patients for 1 month and the results point out the amitriptyline with the greatest weight gain.

Another study shows weight gain among 40 patients in a private psychiatric practise where they took some tricyclic antidepressants, including Amitriptyline. They had an increase in body weight of 1.3-2.9 lbs/month, depending on the dosage and the drug used. It was also the main cause of drug withdrawal among half of the patients where they have had a significant reduction in weight after discontinuing the drug.

How Does Amitriptyline Affect Weight Gain

There are other researchers who were curious about how the Amitriptyline and other tricyclic antidepressants affect weight gain, where they’ve had some interesting findings.

Increased Appetite

This drug affects digestive system by increasing appetite and making you hungry. This is one of the reasons that this medication is being used as an “off-label” drug for eating disorders such as anorexia.

Fat Tissue

Sometimes, when taking certain medications, it can affect metabolism in general. When taking Amitriptyline, it can affect body fat storage due to an altered metabolism of fat. Drugs affect hormone levels resulting in more fat storage. This is best expressed through hormone leptin where it increases the hormone which leads to appetite increase as well and feeling of hunger.

Slow Metabolism

As mentioned above, Amitriptyline alters the hormone levels, making your metabolism go slower. This can also add to fat storage and weight gain results. It is important to take care of proper nutrition while taking this medicine since it can lead to a state of being more prone to gaining weight.

Carbohydrates Intake

When taking this medication, it can increase your appetite and your craving for sweets. This includes carbohydrates which transition into fat in excessive amount when it adds to weight gaining. Another reason for this is where the serotonin gets linked to carbohydrates in the blood, so when it is in a high concentration, your body asks for more carbohydrates to follow the flow of increase.


Another Amitriptyline side effect is sedation where a person can feel fatigue, tired, sleepy and sedated. This also reacts together with a slower metabolism and fat storage change, so when you sleep more and exercise less, there are more chances you will gain weight.

Taste Perception Alteration

After resolving depression, patients can have a feel of the better taste of food since they are in a better mood and they can start to eat more and larger portions which can result in weight gain.

Factors Which Affect Weight Gain When Taking Amitriptyline

Though it is very individual, some factors are well known to influence on weight gain occurrence when taking this medication.


This is a logical one and the weight gain side effect is linked with higher dosages of Amitriptyline. Therefore, it is recommended to take minimal effective dosage which your doctor will prescribe you.

Duration Of Intake

This is another important factor, where those who have been taking this medication for a long time will have more potential of getting weight than those who are in a short amount of time on a therapy. There is also the possibility of tolerance development due to a time span, so patients tend to increase their dosage, which can also lead to a risk of weight gain.


It is important to state that individual differences between people taking this drug and link with weight gain can have to do with genetics. Some people are more prone to fat storage than others, depending on their DNA. It can combine with drug effects and produce an increased side effect.


Amitriptyline is a drug with possible side effects which can lead to an increased appetite and altered fat storage issues, but you are mainly in charge of what you eat and how much you intake. You should eat fewer carbs, drink more water, eat healthy food, sleep well, exercise and avoid stress. You should eliminate fast food and fat from your diet. If you take care of yourself, a drug will have a lower impact on your weight.

How Much Weight Can One Gain With Amitriptyline Intake?

There are many different outcomes and poor study results which testify about a weight scale for weight gaining linked with Amitriptyline usage. Some have gained from 1 to 3 lbs per month when taking it for a longer period.

Does Amitriptyline Cause Everyone To Gain Weight?

Not everyone, but most of the patients, depending on their genetics, lifestyle, dosage and interaction with other medications they use.

Should You Withdrawal Amitriptyline If You Gain Weight?

There is a high incidence of people discontinuing Amitriptyline due to its weight gain side effect. It is about 50% of patients which decide they want to stop using it or to change medication, for which they have to contact their doctor about for a consultation and an opinion of changing the medication. It is important to know that if you monitor your diet and lifestyle, you can minimize the side effects this drug has.