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Have an Underweight Leopard Gecko? (The Causes and Fixes)

Have an Underweight Leopard Gecko? (The Causes and Fixes)

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The purpose of this blog is to share general information and is written to the author's best knowledge. It is not intended to be used in place of veterinary advice. For health concerns, please seek proper veterinary care. In addition, as an Amazon Associate I earn from qualifying purchases.

Do you have an underweight leopard gecko?

As a pet owner, your primary concern is ensuring that your pet is healthy and that its body has a healthy amount of fats that help it fight off diseases and stay warm.

So, you might be concerned when you see your lovely reptile losing weight and becoming too skinny. So why does this happen?

Let’s get to the bottom of why your gecko is on the skinny side. We’ll also suggest a few tips to help your pet reptile gain some weight.

So, let’s dive in.

How Do I Know That I Have an Underweight Leopard Gecko?

Before you say that your gecko is thin, you should know how much it should weigh at different stages of its life.

Once the egg hatches, your leopard gecko will be so tiny, usually weighing around 4 or 5 grams. Yet, its weight is supposed to be between 15 and 20 grams by the time it’s only one month.

Your gecko’s weight will increase gradually until it reaches its mature weight and size. By the age of 18 months, you’ll have a fully mature leopard gecko that should weigh between 40 and 80 grams.

Nevertheless, some bigger geckos can weigh up to 110 grams.

This means that if you have a gecko that weighs less than 40 grams, it’s considered to be underweight.

Your gecko can be naturally underweight, or it might lose weight significantly. Unfortunately, because there’s no official chart for geckos’ weights, it’s pretty hard to determine if your gecko is naturally underweight or hasn’t reached its full mature size yet.

Why Is My Gecko Losing Weight?

You know your gecko better than anyone else.

So, if you start seeing its tail getting skinny, followed by an overall loss of body weight, then there might be something wrong with it.

Geckos can lose and gain weight throughout their lives, but things can be concerning if your pet is getting skinnier and less active. This can happen for several reasons.

Poor Eating Habits

Malnutrition is probably the main reason your leopard gecko might lose weight and become skinnier. Since these animals have high metabolism rates, you need to provide them with high-energy food all the time.

Geckos need to feed on fat-loaded insects like hoppers, Dubia roaches, butterworms, hornworms, mealworms, and crickets to maintain a healthy weight.

You should also feed them regularly, or they’ll start to lose weight because they don’t get enough calories to support their active bodies.

Some pet owners mistakenly think that they can offer their geckos human food.

These insects are carnivores and won’t benefit from eating veggies and fruits. As a matter of fact, they can get really sick because their short digestive tracts aren’t designed to digest fibers and carbs.

Instead, you should ensure they’re eating fatty insects that provide them with all the healthy nutrients they need to survive.

Bad Feeding Habits

You might be the reason why your gecko is losing weight.

Offering food that doesn’t suit your gecko’s size can be too harmful because it won’t be able to benefit from it.

This is why you should watch your gecko’s size, as the food offered to an adult reptile won’t work for a baby one.

The rule is to ensure that the insect you’re offering isn’t bigger than the gecko’s head. Otherwise, it won’t be able to swallow it.

Moreover, you should remove any uneaten insects, especially crickets, as they can bite your pet.

Harmful Parasites

Harmful parasites can infect your leopard gecko, depriving it of absorbing the healthy nutrients from the food it eats.

This means that you might be providing your leopard gecko with a healthy insect-based diet, and it still loses weight because these parasites absorb the nutrients.

The most common parasitic infection is cryptosporidiosis, caused by a parasite called cryptosporidium.

This parasite infects the gecko’s digestive tract and resides in the intestines.

When the reptile eats, the food passes through the intestine, where the parasite absorbs nutrients.

This leads to several symptoms, including watery stool or diarrhea and a stick tail, where the animal starts losing significant weight from its tail.

If it’s left untreated, this condition can lead to starvation and even death because the gecko doesn’t receive the essential nutrients that it needs to survive.

Unfortunately, this condition is highly contagious, and it spreads through fecal matter. This means that if you have one sick gecko, the others are probably going to get sick too.

Metabolic Bone Disease

This disease is caused by vitamin D and calcium deficiency. It can also result from kidney failure, where the body can’t absorb adequate amounts of calcium from the food the gecko eats.

As a result, the gecko’s body starts to absorb calcium from the bones to maintain the functions of various organs and the blood’s quality.

Over time, the bones in the gecko’s body will become soft and rubbery, giving your pet a skinnier look. This condition can be fatal if left untreated.

Egg Retention

If you have a female gecko that is about to lay eggs, you might notice that it’s losing weight because it refuses to eat. This is caused by egg retention.

Egg retention is a condition where the female leopard gecko holds the eggs in her body and refuses to lay them because the conditions in her habitat aren’t favorable.

Your pet will become lazier, and it will avoid eating, so it will lose weight significantly.

Internal Blockage

Remember that your leopard gecko has a short digestive tract and a small digestive system. This means that it can easily get blocked if it eats the wrong items.

This condition is quite common when the gecko eats some of the substrate material. When it feeds on sand or gravel, these particles clog the animal’s intestines, leaving no room for food to pass through.

As a result, the leopard gecko will be unable to eat, and this condition needs to be addressed fast. If left untreated, your poor pet will die.


Geckos can suffer from stress if you don’t provide them with a comfortable habitat that suits their needs.

When your pet feels threatened, it won’t eat, and it will start losing weight.

This can happen when you first introduce a new leopard gecko to the enclosure.

It usually happens when your enclosure is home to too many geckos or other animals that aren’t good companions for this animal.

How to Help My Underweight Leopard Gecko Gain Weight?

Now that you know the reasons why your leopard gecko might be getting skinny, you can try a few remedies, tips, and tricks to maintain its healthy weight.

Provide a Healthy Varying Diet

Changing some of the food that you give your gecko can help with weight gain.

You should provide your pet with some fatty insects and offer different types to see which ones can help your gecko gain weight.

Some insects like crickets, mealworms, and hornworms are packed with proteins, but your gecko might need different types to maintain its health.

Other insects are rich in healthy fats like, waxworms and butterworms. If your gecko is underweight, you might want to add more of them to your pet’s diet to keep it healthy.

Yet, you should think of these fatty worms as treats for your pet leopard gecko, so you shouldn’t provide them regularly as they don’t provide a high nutritional value.

Instead, incorporate them into a healthy diet and make sure that your gecko feeds on them two or three times a week.

Gut Loading Insects

Before you provide your gecko with food, make sure that you gut-load the insects first.

This refers to the process of allowing these insects to feed on high-nutritional value food before you offer them to your pet reptile.

The food the insects eat nourishes their bodies, and the nutrients in the food will be passed onto the gecko’s body, making them tastier and healthier.

Unfortunately, commercially available insects and worms aren’t fed properly, so if you have a pet gecko, you might want to gut-load the insects and worms to keep them healthy.

This can be done by offering your prey different types of food, including fish flakes, chicken starter feed, veggies, and fruits. You can also add some supplements to their food to make them healthier.

This should be done one or two days before offering these insects to your pet gecko, or the insects will start consuming these nutrients that won’t benefit your pet.


Dusting is an important feeding technique that you should follow if you have a sick or underweight gecko.

This is the process of dusting the gecko’s food with a vitamin D and calcium supplement before your pet eats it.

It can be done every time you feed your pet gecko by placing the insects in a zip lock bag with the supplement and shaking it until their bodies get covered with the nutritional dust.

This solution can help if your gecko has a metabolic bone disease, and it will soon help restore the gecko’s health.

Final Thoughts

You need to understand the ideal weight of your leopard gecko at every stage of its life.

If your gecko is losing weight, you might not be offering the correct type and amount of food. It might also be suffering from an illness that makes it unable to eat.

It’s important to offer protein and fat-rich insects to help your gecko maintain its healthy weight. Gut-loading insects and dusting them with healthy supplements is also crucial for the gecko’s health.

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