Underweight Crested Gecko? 12 Causes And Solutions

Underweight Crested Gecko

As an owner you want your Crested gecko to live a happy and healthy life. However, there are some health problems to look out for and one of them is weight loss. Some of the possible causes for underweight Crested gecko are diet, stress, new environment, illness. In most cases this issue can be easily resolved.

This article will help you determine what’s the cause for your Crested gecko’s weight loss and how to help them get back to a healthy weight.

To get to the bottom of the problem, we will be discussing the following topics:

  • What are the signs of underweight Crested gecko
  • Average Crested gecko weight and tracking
  • Causes and solutions for underweight Crested gecko
  • Tips and tricks to help your Crested gecko gain weight

What Are The Signs Of Underweight Crested Gecko?

Underweight Crested Gecko

Underweight Crested gecko can be a great concern for any owner. Before panicking, first ensure that your gecko is really showing the signs for underweight Crested gecko such as:

  • Slim body and legs
  • Ribs and hip bones are visible
  • No rounding of the belly
  • Loss of appetite
  • Lack of calcium sacks

Average Crested Gecko Weight

The average healthy Crested gecko has a stocky body build, especially in the neck region.

However, if you are concerned that you might have an underweight Crested gecko, the first thing you need to know is – what is the average weight of a healthy Crested gecko.

Use the table below as a guide on the average weight of Crested gecko by age

1 to 4 months2 to 5 grams
5 to 9 months7 to 17 grams
10 to 15 months21 to 33 grams
16 to 24 months34 to 35 grams

It’s also important to remember that babies and juvenile geckos might appear thinner with their ribs more visible than in adults. This is normal and once they get older, they will start to fill out.

Crested Gecko Growth Rate

A baby Crested gecko normally will grow around 1 gram every 2 weeks without crickets/roaches in their diet. Whereas, if you include insects in their diet, the additional protein will increase their growth rate to around 1.5 to 2 grams every 2 weeks.

Tracking Your Crested Gecko Weight

To ensure you don’t end up with an underweight Crested gecko, it’s recommended to track your gecko’s weight. This can be done by recording their weight every month in a diary.

To correctly track your Crested gecko’s weight, follow these tips:

  • For sick and newly bought geckos – weigh once a week
  • Weigh your gecko before feedings
  • Use a digital scale that weighs in (.10) grams. You want it to be as accurate as possible as hatchlings weigh as little as 1.5 grams
  • Using the scale, you can weigh the food dish at night and then again in the morning to check if any was eaten

Causes And Solutions For Underweight Crested Gecko

There is only one real cause that can result in underweight Crested gecko and is to do with food:

  • Not eating enough
  • Lack of nutrients in food
  • Completely stopped eating

Although it might seem obvious that eating is the reason your gecko is underweight, we want to know why are they not eating.

For that reason, we are looking at all the possible causes and solutions for your Crested gecko not eating and subsequently becoming underweight:

  • New environment is stressing them
  • Wrong temperature and humidity in tank
  • Tank/Enclosure is wrong size
  • Incorrect tank/enclosure setup
  • Bullying
  • Diet
  • Fussy eaters
  • Breeding period
  • Shedding
  • Stress
  • Sickness
  • Impaction

1.New Environment Is Stressing Them

If your have just bought/adopted a new Crested gecko, you should expect the first few weeks to be very stressful for them. The stress of getting used to a completely new and unfamiliar environment can result in them not eating.

Losing a few grams can be noticeable in geckos, so not eating at all or barely eating for 2 weeks can result in underweight Crested gecko.


This behavior is expected and usually resolves by itself in 1 to 2 weeks. However, you can follow the advice below if you want your Crested gecko’s settling period to go quicker and smoother:

  • Avoid handling your Crested gecko the first two weeks. After two weeks have passed you can start holding your gecko for 1 to 2 minutes each time. Learn more on what is the correct handling technique here How To Hold A Crested Gecko: Tips On Handling Crested Gecko
  • Change their food and water in afternoon whilst the gecko is sleeping
  • Make slow movements such as opening the tank very slowly
  • Monitor their behavior – are they improving or staying the same?

If your Crested gecko is not improving after 2 weeks and is still not eating, look at other possible causes for this behavior.

2. Wrong Temperature and Humidity In Tank

Possible cause for underweight Crested gecko is incorrect temperature and humidity in their tank. Providing your Crested gecko with the correct environment is essential in maintaining a healthy weight.

Too High/Low Temperature

If the temperatures are too low or too high, it can result in your gecko not eating and subsequently in underweight Crested gecko.

In the wild, the Crested gecko will slow down in the winter seasons. This includes less movement, less eating and hunting. That’s why if the temperature in their tank is anything below 70°F, it will result in your gecko preserving all their energy by not moving and not eating. This will result in weight loss.

On the other hand, if the temperature in the tank is too high, your Crested gecko can suffer from heat stress. This is very dangerous and will result in your Crested gecko not eating. If not corrected quickly, it can even cause death.


The Crested gecko is healthiest when living in temperatures between 72°F to 75°F. Therefore, that’s the temperature their tank should be kept at.

Don’t allow it to reach 80°F or more as that can cause heat stress and result in a dehydrated Crested gecko. To learn more about how to help a dehydrated Crested gecko click here Dehydrated Crested Gecko: Crested Gecko Dehydration Signs And Treatment

To track the temperature levels of your gecko’s tank, it’s recommended to use a digital thermometer.

Too High/Low Humidity

Same as temperature levels, humidity is also essential to your Crested gecko’s weight and appetite.

If the humidity in the tank is too low, it can affect your gecko’s appetite and result in underweight Crested gecko.


To ensure the tank has the right levels of humidity, stick to the following rules:

  • Humidity levels need to be kept at 60% during the day and at 80% during the night. It shouldn’t be constantly high
  • Use a spray bottle with purified water (never use tap water) to mist the tank
  • Mist twice per day – light mist in the morning and a stronger one at night
  • Use a digital hygrometer to measure the humidity levels
  • By misting the tank right after you put the food, they might be more eager to eat

3.Tank/Enclosure Is Wrong Size

Another factor that affect your Crested gecko’s appetite and can eventually result in underweight Crested gecko is wrong tank size.

If the tank is too big and your Crested gecko too small, they will feel overwhelmed and will be unable to find their food/water bowl. Overtime this will result in your Crested gecko losing weight as they won’t be eating.


Use the table below for guidance on the right size tank for your Crested gecko

Crested Gecko’s AgeTank Size
9 to 18 grams6 gallon
18 to 20 grams20 gallon
25+ grams30 gallon

4.Incorrect Tank/Enclosure Setup

Large Enclosure With Many Decorations

If you have an underweight Crested gecko, a good thing to check is if their tank/enclosure set up is correct. If there are essential parts of the setup missing such as decorations, hiding spots, etc., it can decrease your gecko’s appetite.


Ensure that your Crested gecko’s tank has the following as a minimum:

  • Some artificial logs, plants
  • Hiding spots. This can be as simple as tube roll from toilet paper. Hiding spots are very important for your gecko’s well-being. If there are no hiding spots, it can result in your gecko feeling too scared to even move to find their food bowl
  • Vertical terrarium. In the wild, Crested geckos are used to spending their time in branches. A vertical tank will provide them with that height

To learn more in detail about the Crested gecko habitat setup click here Crested Gecko Habitat Setup: How To Build A Perfect Tank


If you have more than one Crested gecko living in the same tank, it can lead to bullying amongst the tankmates. If a Crested gecko is being bullied, they will stop eating and can become underweight.

Bullied gecko is often also an underweight Crested gecko.


If this is your case, the best thing to do is to separate the geckos and provide each one with their own enclosure.

Ensure that the new tank for all Crested geckos are the right size, have some decoration and hiding spots.

To learn about what Crested gecko combinations you should avoid housing together, click here for the full guide Can Crested Geckos Live Together? Top Tips On Housing Crested Geckos


Underweight Crested Gecko

One of the main reason for your gecko not eating and being underweight is diet. Not getting the proper nutrition from their diet can result in underweight Crested gecko.

Some types of diets such as the homemade diet can lack nutrients. This type of diet requires constant tracking and having a good understating of the Ca:P (Calcium: Phosphorus) ratio in foods, oxalic acid, vitamins and minerals content.


In the wild, Crested geckos’ natural diet consists of variety of plants, fruits, bugs and insects.

Crested gecko’s need foods with 2:1 or better Ca:P ratio and low oxalic acid content for a staple diet. If your gecko doesn’t get the amount of Calcium they need, it can result in Metabolic Bone disease and it can be the reason for your Crested gecko’s weight loss.

In captivity, there are a few options for your Crested gecko’s diet:

  • Commercial diet. Commercial diets have been designed to meet your gecko’s needs and provide the nutrition they need in order to grow to their full potential. Popular brands are Repashy and Pangea
  • Homemade diet. Homemade Crested gecko diets are considered more risky and are not recommended for unexperienced reptile owners. If you don’t understand the balance of nutrients that your gecko requires, it can be risky for your pet’s health
  • Treat. In addition, you can feed your gecko insects and healthy fruits as an occasional treat (1 to 2 times a month). It’s very important that the fruits have the right nutrients, Ca:P ratio and oxalic acid.

The following diets should be completely avoided:

  • All-insect diet
  • Baby food

Both of these diets are out-dated, don’t have the necessary nutrient and can be harmful to your gecko’s health. Furthermore, because of the lack of nutrients, it can result in an underweight Crested gecko.

It’s important to remember that Crested gecko’s metabolism is different from mammals. In some cases, the gecko might not eat for a few days, up to a week and that can be normal.

However, if your gecko hasn’t eaten for over 1 week, you should look into the possible causes for the behavior.

7.Fussy Eaters

If your Crested gecko is a fussy eater, it can result in them not liking certain foods and refusing to eat. This can lead to your Crested gecko being underweight.


Try different food consistencies. Some like it more runny and liquidly, whereas others prefer it thicker.

Other solutions include:

  • Switching up the food brands – Pangea to Repashy or vice versa
  • Switching up the flavors

8.Breeding Period

In some cases your Crested gecko can lose weight during natural processes such as breeding. This lack of appetite during breeding is especially observed in female geckos.

During that period and especially just before laying the eggs, female Crested geckos tend to avoid food which can result in weight loss.


If this is the reason for your underweight Crested gecko, there is nothing to worry about and it should resolve on its own.

However, you should still monitor your gecko and ensure they don’t lose too much weight during breeding as it can be detrimental to their health.


Another normal process that your Crested gecko goes through that can result in your gecko’s weight loss is shedding. During the shedding, your Crested gecko might avoid food 2 to 3 days before and/or after shedding.


Once the shedding is fully completed, your Crested gecko should be back eating in a few days. This is nothing to worry about and it should resolve on its own.


Crested geckos are very fragile animals that get stressed easily. One of the most common causes for underweight Crested gecko is stress.

If your Crested gecko is stressed for whatever reason, it can result in loss of appetite and weight loss. Not only that but prolonged stress can have a serious impact on their health.


In order to find a solution, you first need to establish what’s causing stress to your Crested gecko. Some of the possible causes include:

  • Insufficient nutrients in diet
  • Incorrect habitat set up – size, decorations
  • New environment
  • Sudden change in diet
  • Other tankmates
  • Incorrect temperature and humidity levels
  • Incorrect handling

To learn everything about stress in Crested geckos including solutions, click here Crested Gecko Stress Signs: How To Prevent And Treat Stress


Impaction is when your gecko has ingested something that they couldn’t pass and it’s lodged inside of them. If your gecko is impacted, it can result in loss of appetite and subsequently in underweight Crested gecko.

Symptoms of impacted gecko include:

  • Round belly
  • Sudden weight gain of few grams
  • Constipation
  • Loss of appetite


To help your Crested gecko pass the mass that’s lodged inside of them, follow these tips:

To avoid impaction in the first place, do the following:

  • Substrate. It’s recommended to use paper towel substrate as any loose substrate can be ingested by your gecko and result in impaction. This is especially true for baby or juvenile geckos
  • Decorations. Don’t use small rocks or sand as decoration as they can be ingested by your gecko and even result in death
  • Insects. Never feed your Crested gecko bugs or insects that are larger that the space between their eyes or bugs with hard shells such as beetles


Underweight Crested gecko can be a serious concern for any owner. Even bigger concern is if their weight loss is a symptom of an illness.

Weight loss is one of the symptoms in many Crested gecko illnesses such as parasites, infections, Metabolic Bone disorder and other.


If you suspect an illness, first eliminate all other possible causes that we spoke about in this article and second – look out for other symptoms.

Other symptoms for parasites include

  • Weight loss
  • Vomiting
  • Diarrhea
  • Loss of appetite
  • Foul smelling poop

Other symptoms for Metabolic Bone disorder include:

  • Wavy tail
  • Soft jaw
  • Curved limbs
  • Tiredness
  • Not eating

If you have eliminated all other possible causes and you still think your Crested gecko is sick, take your gecko to the vet for further tests.

To learn more about causes and treatment for sick Crested gecko click here Crested Gecko Stress Signs: How To Prevent And Treat Stress

Tips And Tricks To Help You Crested Gecko Gain Weight

If you have an underweight Crested gecko on your hands that’s refusing to eat, there are a few tips and tricks you can try to improve your gecko’s appetite.

  • Hand feeding. You can try to hand feed your gecko by placing a small amount of food on your finger and taking it to your gecko’s mouth. Be careful as your gecko can become dependent on hand feeding and refuse to look for food on their own
  • Pipette/syringe feeding. You can use a small syringe (no needle) or pipette to administer the food. This is not done with force but by taking it close enough to your gecko’s mouth, so they can lick it
  • Bugs/insects. You can offer your gecko a bug/insect to stimulate their appetite. However, be careful to not overfeed them as bugs can be addictive to Crested geckos and can result in them not wanting to eat anything else. Learn about feeding your gecko waxworms here Can Crested Geckos Eat Waxworms? Pro’s And Con’s
  • Fruit puree. You can offer your gecko some healthy fruit puree that can improve their appetite such as papaya. However, not all fruits are good for your gecko!
  • Food consistency. It’s important to remember that each Crested gecko has their own preference of food consistency. Some like it more runny and liquidly. Whereas, others prefer it thicker. Try switching up the consistency of the food to see if that improves their appetite
  • Misting. By misting the tank right after you put the food, geckos are usually more eager to eat
  • Food Location. Place food bowls in more than one location in your gecko’s tank. Ideally, you should place one food bowl on the ground and one on a feeding ledge at a height

Final Thoughts

Underweight Crested gecko can be very stressful for any owner. The first thing to do is to explore all the possible causes.

The main reason for weight loss in Crested gecko is food related. They are either not eating at all, not eating enough or their food lacks nutrients.

If your Crested gecko is not eating, you ned to find the reason why. The possible causes, we discussed in this article were:

  • New environment is stressing them
  • Wrong temperature and humidity in tank
  • Tank/Enclosure is wrong size
  • Incorrect tank/enclosure setup
  • Bullying
  • Diet
  • Fussy eaters
  • Breeding period
  • Shedding
  • Stress
  • Impaction
  • Sickness

A few tips and tricks that can help get your gecko’s appetite back include:

  • Hand feeding
  • Using pipette to feed them
  • Bugs/insects/fruit purees
  • Misting the tank before you put down their food
  • Placing the food in more than one location – on the ground and on a feeding ledge

If the solutions suggested in this article haven’t worked for you, it’s very likely that your Crested gecko is sick. In that case, you should take your gecko to the vet for further tests.

Related Topics Q&A

Is My Crested Gecko Eating?

If you are worried that your Crested gecko is not eating, you should know that these geckos don’t eat much to start with. It might appear that they are not eating at all but that might not be the case.

To determine if  your Crested gecko is really not eating, you should check the following:

  • Poop – In order to see if your Crested gecko is not eating, you should check their poop. If there is poop, it means they are eating. As the gecko’s poop is very small, it’s might be hard to find it
  • Weight – Know what is the average healthy weight for your Crested gecko by age
  • Food bowls – Use a small food bowl such as bottle cap or wax paper instead of a large feeding bowls/dishes. This way it will be easier to tell if the food has been eaten. Also, you can weigh the food bowl before and after to see if any has been eaten

Learn more about Crested gecko not eating here Crested Gecko Not Eating? 11 Causes And Solutions


My name is Iliyana and I'm a passionate animal lover and pet owner. As there is significantly less information online about unusual and exotic pets, I decided to found this website and recruit expert writers to help pet owners.

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