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Why is my red iguana turning black?

There are a few potential reasons why your red iguana may be turning black. This drastic color change can be alarming for iguana owners, but in most cases there are straightforward explanations and solutions.

Common Causes

Here are some of the most common reasons an iguana’s skin color might shift from red to black:

  • Shedding – Iguanas shed their skin regularly as they grow. Before a shed, their colors often appear duller. The old skin comes off in patches, revealing the brighter new skin underneath.
  • Stress – Stress caused by environmental changes, improper housing, illness, or other factors can cause physical changes like blackening skin.
  • Temperature – Iguanas are cold blooded. If they get too cold, their skin color may darken in response.
  • Brumation – In winter months, iguanas naturally enter a dormant state called brumation. Their color dims during this time.
  • Diet – Poor nutrition from lack of proper fruits and vegetables can contribute to color loss.
  • Illness – Certain illnesses or infections can physically alter an iguana’s skin pigmentation.
  • Maturation – As iguanas age, some naturally develop darker colors on parts of the body.


One of the most common reasons for color change in iguanas is shedding. Iguanas shed, or molt, their skin every 4-6 weeks as they grow. New skin is generated to replace the old skin in patches across the body. In the weeks leading up to a shed, iguanas often appear dull in color.

Their bright new colors will return after the old skin fully comes off. Helping your iguana through a proper shed is important for their health and coloration. Make sure humidity levels stay around 50-60% and provide a rough surface for them to rub against.


Stress is another factor that can cause your red iguana to turn black. Stress raises cortisol levels in iguanas, which impacts their physiology in various ways, including skin pigmentation.

Causes of stress include:

  • Improper housing – An enclosure that is too small, lacks hiding spots, or has poor lighting can stress your iguana.
  • Incorrect humidity or temperature – Iguanas require specific humidity and day/nighttime temperature ranges to thrive.
  • Loneliness – Iguanas are social and can become stressed if they do not have interaction with other iguanas.
  • Overhandling – Too much direct contact stresses iguanas, who are largely solitary animals.
  • Environmental changes – Redecorating their enclosure, moving them to a new home, introducing new pets can cause stress.
  • Illness – Pain, inflammation, and infection due to health issues elevates stress hormones.

Correcting any sources of stress, like enhancing their enclosure or minimizing handling, can allow your iguana’s colors to return over time. Consult an exotic vet if illness is suspected.

Low Temperature

Iguanas are cold blooded reptiles, so their body temperature directly impacts their physiology, including skin pigmentation. If your iguana is consistently too cold, their color may darken as a response.

Red iguanas need daytime temperatures between 95-100°F to properly regulate body functions. If the ambient temperature drops below this range, they can rapidly become too cold.

Ensure their basking area reaches appropriate temperatures using a heat lamp or ceramic heat emitter. At night, temperatures can drop to 70-75°F. Tracking your enclosure temperatures daily helps make adjustments as needed.


In winter months, iguanas enter a hibernation-like state called brumation. Their metabolism slows dramatically during this time so their bodies can conserve energy and stay warm.

As part of this process, iguanas often lose their bright colors and appear darker. They may stop eating as much. This is normal seasonal behavior if the color change aligns with winter.

Make sure the enclosure temperatures remain stable during brumation. Providing supplemental heat can help prevent severe cooling. The darkened colors should return after a few months as normal activity resumes.

Poor Diet

Nutrition heavily impacts iguana health – including their skin and colors. Red iguanas need a diverse diet of fruits and vegetables to thrive. Lack of proper nutrition can cause their colors to become muted or darken.

Key diet components to provide daily include:

  • Leafy greens – kale, mustard greens, dandelion greens
  • Squash
  • Sweet potatoes
  • Carrots
  • Berries
  • Mango
  • Papaya

A nutritional deficit often arises from feeding too many starchy vegetables and fruits – like apples, bananas, potatoes. Consult an exotic vet if you notice your iguana refusing food or losing weight.


In some cases, blackening skin may signal an underlying health issue in red iguanas. Skin discoloration and darkening patches can indicate:

  • Fungal infection
  • Bacterial infection
  • Parasites
  • Skin irritation or injury
  • Kidney or liver problems
  • Metabolic bone disease

Schedule an exam with your exotic vet if your iguana’s skin changes rapidly or appears inflamed. Treatments like antifungals, fluid therapy or dietary changes may be prescribed to resolve the issue and restore normal colors.


Finally, some natural darkening of certain body parts can occur simply as a red iguana matures into an adult. As iguanas age, black or darkened scales may appear on sections like the legs, back, tail or face.

These maturation changes tend to happen slowly over time, rather than rapidly. They occur most frequently after 2 years old. Some reddening should remain visible on other areas like the head and sides.

As long as your iguana is acting healthy overall, eats well, and still exhibits some bright red pigments, this gradual shift is natural. Their colors may also become generally more muted as adults compared to the vivid brightness of juveniles.

Diagnosing the Cause

Determining the underlying reason your red iguana changed color allows you to take appropriate action. Here are some ways to identify why they lost their red hue:

  • Shedding – Skin will appear flaky before turning black. Color returns after molting.
  • Stress – Behaviors like decreased appetite or activity plus environmental issues provide clues.
  • Temperature – Consistently cool ambient temps below 95°F signal a heating problem.
  • Brumation – Color change aligns with winter months when they are less active.
  • Diet – Review their food intake. Lack of vegetables, vitamins could be deficiency.
  • Illness – Noticeable physical symptoms like wounds, swelling, discharge or weight loss.
  • Maturation – Gradual darkening of certain areas over months to years, starting after age 2.

Large portions of your iguana turning totally black within a few days or weeks is not normal. Seek input from an exotic vet when rapid, widespread color loss occurs along with concerning symptoms.

Treatment and Prevention

Getting to the root of your iguana’s skin color change allows you to take steps to restore their bright red hues. Here are tips to resolve various causes and prevent future darkening:


  • Provide rough surfaces to help them shed fully
  • Mist enclosure for humidity between 50-60%
  • Do not peel skin prematurely


  • Adjust enclosure layout and access to hiding spots
  • Maintain optimal temperature gradient
  • Limit direct handling
  • Introduce companion iguanas


  • Use heated basking bulb to reach 95-100°F in daytime
  • Position heat lamp at optimal distance from basking area
  • Keep ambient temperatures 70-75°F at night


  • Increase dark leafy greens, veggies, fruit
  • Decrease starchy produce like potatoes
  • Dust food with calcium + vitamins
  • Provide clean drinking water daily


  • Schedule exam with exotic veterinarian
  • Run diagnostics tests if needed
  • Follow treatment plans like medications, fluid therapy
  • Make dietary changes as prescribed

When to Seek Help

Occasional mild darkening of iguana skin during shedding or winter dormancy is normal. But seek prompt veterinary care if you notice:

  • Rapid blackening of large areas
  • Dark raised bumps, lesions or swelling
  • Loss of appetite or lethargy
  • Weight loss
  • Visible wounds
  • Discharge from nose or eyes
  • Diarrhea
  • Labored breathing

Skin changes in conjunction with these symptoms could signal a medical problem requiring treatment. Catching issues early maximizes the chances of restoring your iguana’s health and bright coloring.


A red iguana spontaneously turning black is often alarming for owners. But in most cases the color shift has an explainable cause. From shedding cycles to brumation to dietary changes, identifiable factors are usually behind the altered pigmentation.

Understanding the various reasons an iguana loses its bright color helps you evaluate the cause in your own pet’s case. With proper treatment of any underlying issues, plus adjustments to their environment and diet, your red iguana’s vibrant hues can return.

Regularly monitor their skin and overall health. Consult an exotic vet promptly if rapid color change occurs along with other symptoms. Catching problems early is key to getting your beloved iguana back to full red glory.