Gabapentin and Weight Gain

gaba2Gabapentin (Neurontin) is an anticonvulsant used for treating seizures and nerve pain (usually caused by herpes zoster). It can be also a drug of choice for restless legs syndrome (RLS), migraines, hot flashes, anxiety disorders, etc. It is commonly prescribed as an off-label drug for any of the conditions mentioned above. It has to do with its low potential for abuse and low level of addictiveness. It does work as an anticonvulsant and as an analgesic, so it can be used prior to surgery to calm down the anxiety and provide painkiller effects. It has a mechanism which acts on GABA neurotransmission and it results in analgesics and anticonvulsants results.

Some people have experienced its side effects or they haven’t noticed positive effects on them while using the medication, therefore, they wanted to discontinue the drug from its use. When talking about possible side effects of a medicine, some people have reported weight gain problems. This can be one of the reasons why some want to withdrawal the Gabapentin.

Does Gabapentin Cause Weight Gain As A Side Effect?

Gabapentin is usually considered as a “weight neutral” drug. A small percent of people have reported they gained weight during therapy with Gabapentin. Approximately 3% of all people will notice any weight changes when using this drug. It is usually linked with a higher doses therapy where some people can gain weight when using it for some time. A study was conducted among 44 patients who were taking high doses of Gabapentin longer than 12 months. They were taking it for a seizure treatment and they were receiving more than 3000 mg per day. 10 patients gained weight over 10% and 15 patients have gained weight from 5 to 10%. This can be due to different factors among each individual since some of the patients didn’t have any fluctuations in weight and others have lost some weight. It can be a question of individual characteristics, life choices, lifestyle including physical activity and diet.

How Does Gabapentin Cause Weight Gain?

Even though Gabapentin isn’t considered positively weight gain changer, it can happen with some patients. For those who notices, it isn’t one factor that is responsible for these outcomes. There are numerous things which can cause this kind of effects. Here are some possibilities.

Appetite Increase

Gabapentin is a drug which can influence on an appetite. Some people have reported a significant increase in urge to eat. It can be hard to cope with, so a lot of people get to a point where they can’t control it and get weight over time.

Food Cravings

Some people have reported increased desire for certain food and carbohydrates. They start to eat the sugary food and this can frequently result in obesity and overeat the sweets. It can cause high blood sugar and other problems as well.


Due to its analgesic effects, individuals can feel like they are tired all the time or they are slow and drowsy. It can be a result of your slow metabolism which can result in fatigue. This can be a reason of a low physical activity and not enough strength to move and be active which can outcome in weight gaining.

Arousal Reduction

Gabapentin is a drug which does not have a direct impact on a GABA in the brain but reacts with voltage-sensitive Ca2+ channels. It’s mechanism actions were not fully described, but it does lead to hyperalgesia and prevents seizures among human, preventing brain responses. It cuts the action of a sympathetic nervous system, which results in arousal reduction. Person’s who are on Gabapentin drug therapy may struggle with energy to workout.

Slow Metabolism

Gabapentin is a drug which will eventually develop sympathetic nervous system reduction and will slow down the metabolism. This can slow down the fat-burning processes in the body, as well as speed reduction during digestion which can also lead to increased lipids storage. You can also have bad diet and exercise routine which combined with slow metabolism can lead to gaining weight.

Low Energy

Gabapentin reacts with cortical neurons at auxiliary subunits of voltage-sensitive Ca2+ channels. It increases the concentration of GABA which is an inhibitive neurotransmitter. It reduces the axon excitability and causes inhibition of noradrenergic system. That way, you will have less energy and strength. It can result in low energy which can lead to less movement and low physical activity.

Food Cravings

When on Gabapentin, some people claim that they’ve had cravings towards carbohydrates and sugary food. It can end up in overeating and get more and more sugary food which can result in weight changes and gain some extra pounds.

Hormone Levels

It is possible to have alterations among hormonal levels, although it isn’t obligatory while taking this medication. It can lead to more fat storage, slower metabolism and gaining weight.

Water Retention

Water retention can also lead to weight scale change. It can be a possible side effect and you might feel bloated and drowsy. It is a possible side effect which does not have to happen in all people using this medication, but it can be accompanied downside.

Taste Improvement

Some people have noticed a change in their taste receptors while taking Gabapentin. This can lead to changes in taste sensation and result in eating more since some food can taste better than before. This can be a reason of eating more and gaining weight.

Social Eating

When you feel bad or you have a certain condition which prevents you from social life, it can be hard for you. When that pain or seizure attacks go away with taking Gabapentin, you can feel more outgoing and be more up for going out with friends which can result in many dinners, going to restaurants, snacks, ice creams, etc. You may not even notice a change in your eating routine and you may eat bigger portions, thus, your weight may increase.

Factors Which Can Influence Weight Gaining During Gabapentin Intake

There are some things which you may want to consider when you’re gaining weight or when you’re worried about it. These factors are individual factors, time span, dosage, lifestyle, genetics, other drugs interaction.

Time Span

Those who take Gabapentin over a longer period of time are more prone to gaining weight. If you are on Gabapentin in a short period of time, you might not notice any changes.


It is not a proved fact that dosage can have an impact on weight changes, but it can happen among some people. It is more common among those who are on a higher dosage therapy.

Drug Interaction

When taking Gabapentin, it is important to consider other drugs in combination with it. Some drugs may cause weight gaining due to their accompanied symptoms. It can be alcohol as well, as some toxic drugs.


With some people, even when having a good diet, lifestyle, and exercising, they gain weight, while others having bad choices lose weight. It has to do with their genetics where it affects certain gene expression and it can end up in different reactions to the environment.

Even when not on a drug such as Gabapentin, it is important to take care of yourself and have healthy choices. Eat well, sleep well, exercise, drink fluids, cut the carbohydrates from your diet and have some relaxation in order to avoid any stress and stressful behavior such as overeating.


    • Your weight gain is influenced by your medications and your lifestyle. You will find benefit in maintaining a plant based diet. You may want to develop an exercise regimen of half an hour each day. If you continue to gain weight and you are maintaining a healthy lifestyle, then speak with your medical professional about your concerns. Best of luck, Linda!


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