Iguana iguana
Green Iguana
Green iguanas are sold small and appealing but grow into large, powerful, potentially defensive animals needing room-sized enclosures. They suit only committed, experienced keepers who plan for the true adult animal from day one.
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At a glance
- Scientific name
- Iguana iguana
- Family
- Iguanidae
- Origin
- Tropical rainforest canopy of Central and South America and the Caribbean
- Lifespan
- 12–20 years
- Adult size
- 1.2–1.8 m including tail
- Weight
- 4–8 kg
- Temperament
- Can be flighty or defensive, especially unhandled adults; strong tail whip and claws
- Activity level
- Moderate; active climbing and basking through the day
- Social needs
- Low toward humans without consistent early handling; largely solitary
- Intelligence
- Good spatial learning of enclosure layout and basking routine
- Noise
- Silent
Housing and environment
- Housing
- Custom-built enclosure at least 2 x 2 x 2.5 m for an adult, as commercial vivaria are almost always too small
- Space requirement
- Tall, climb-rich space is essential; floor area alone is not enough
- Temperature
- Basking spot 35–38°C, ambient 26–30°C, night drop to 22–24°C
- Humidity
- 65–75%
- Exercise
- Extensive climbing space; adults need room to move that few households can provide long-term
- Grooming
- Periodic shedding assistance in low humidity; nail trims for indoor-kept individuals
Life stages and changing needs
Expanded care guidance · Updated 7 October 2026 · Not professionally reviewed
Juvenile
A young green iguana is small, fast and defensive, and this is the stage where patient, consistent handling determines whether the adult is tractable or dangerous. Juveniles need a tall enclosure with strong climbing branches, a basking zone around 35 degrees Celsius, high humidity and powerful UVB lighting; the cute hatchling in a small tank will become a 1.5-metre lizard within a few years, and anyone considering the species should plan for the adult enclosure — room-sized — from the outset.
Adult
Adult iguanas need enormous, custom-built enclosures with substantial heat, UVB, humidity and climbing space, plus daily interaction to stay tame; a bored or under-socialised adult iguana is powerful enough to cause serious injury with tail, teeth and claws, and males commonly become aggressive during breeding season. This combination of size, strength, specialist housing and longevity — fifteen to twenty years — is why iguanas are among the most frequently surrendered reptiles, and they suit only keepers with genuine space and experience.
Senior
Older iguanas often develop kidney disease, arthritis and the long-term consequences of any earlier dietary or lighting mistakes. Maintain the same heat and UVB standards — older bones still need them — provide easier routes to basking spots, and schedule regular bloodwork with a reptile vet, since kidney decline is common and manageable when caught early. Weight, appetite and stool quality are the most useful home-monitored indicators of how an ageing iguana is doing.
Diet and feeding
Strictly herbivorous: dark leafy greens, vegetables and limited fruit; no animal protein
Green iguanas are strict herbivores: the diet should be built on calcium-rich leafy greens such as collard, mustard and turnip greens, with grated squash, green beans and small amounts of fruit, dusted with supplements as advised by a reptile vet. Animal protein — including dog food, insects or egg — damages the kidneys over time and must not be fed, despite older care sheets recommending it.
Avoid iceberg lettuce and spinach as staples, and be cautious with brassicas and oxalate-rich greens, which bind calcium. Fresh water for drinking and a large container for soaking should be available, since iguanas often defecate in water and it needs frequent changing; proper hydration is a pillar of kidney health in this species.
Daily care and ongoing checks
Every day
Verify basking and ambient temperatures and humidity every day, and replace UVB lamps on schedule, because an iguana can look normal for months while inadequate UVB quietly destroys its skeleton. Mist the enclosure and refresh soaking water daily.
Regular maintenance and prevention
Watch posture and behaviour: a healthy iguana basks alertly, climbs and eats with enthusiasm. Hiding at the cool end, a darkened colour, twitching toes or a soft, swollen jaw are early signs of metabolic bone disease or stress, and any change in a tame adult's temperament — new aggression or new lethargy — deserves attention rather than dismissal.
Behaviour and compatibility
Basking, climbing, head-bobbing displays, tail-whipping and biting when threatened
- With children
- Not recommended; adults are strong enough to cause serious scratch or bite injuries
- With other animals
- Solitary housing only
- Training difficulty
- High; consistent gentle handling from hatchling age is the only realistic way to produce a tolerant adult
Health
- Metabolic bone disease from inadequate UVB or calcium
- Abscesses from substrate injuries
- Egg binding in females
- Renal disease linked to poor diet
Needs a reptile-experienced vet familiar with the species' particular UVB and calcium requirements
Special care requirements
The scale of adult housing, UVB provision and handling risk make this one of the most commonly abandoned reptile species
Arboreal verticality and metabolic bone prevention
Green iguanas are powerful, high-climbing lizards that quickly outgrow standard enclosures and require a significant commitment to vertical space. Strict adherence to calcium-supplemented dietary schedules and consistent UVB exposure is essential to prevent metabolic bone disease throughout their growth.
Before you take one on
Sources and further guidance
These welfare and veterinary resources inform general husbandry advice; they do not certify this profile or replace a species-experienced professional. Confirm exact environmental settings and feeding plans for your animal.
Can your home meet green iguana needs?
- Plan for a lifespan of 12–20 years, including holiday cover and, where one is available, a vet familiar with this species. Lifespan ranges are not guarantees.
- Arrange the social setting before arrival. Social guidance for this species: Low toward humans without consistent early handling; largely solitary. Do not assume another animal of any species is a suitable companion.
- Habitat priority for this species: Tall, climb-rich space is essential; floor area alone is not enough. Make sure your setup can provide this consistently. Measure temperatures and humidity with thermometers and a hygrometer rather than guessing.
- Key care point: The scale of adult housing, UVB provision and handling risk make this one of the most commonly abandoned reptile species. Discuss diet and any specialist needs with the supplier, rescue and a vet who treats this species, and check local legal requirements before acquiring an animal.
Educational reference, not an individual diagnosis or a verified professional review. Read our editorial policy.
Guidance libraries and further reading
These organisations publish relevant guidance. Their links are further reading, not evidence that they have reviewed this page.