Leopard geckos (Eublepharis macularius) have been captive-bred for over 50 years, making them one of the most well-understood reptile species in the hobby. They are beginner-friendly, handleable, and relatively forgiving of minor husbandry mistakes — but their dietary needs are not flexible. Get the feeding protocol right, and your gecko can live 15–20 years in excellent health. Get it wrong, and metabolic bone disease, obesity, or nutritional deficiency will follow.

The Obligate Insectivore Rule

Leopard geckos eat insects and only insects. In the wild, they consume beetles, crickets, moths, and other small invertebrates. Their digestive system is built for animal protein — they lack the gut flora to ferment plant material and do not produce the salivary enzymes needed to begin carbohydrate digestion from starches and sugars.

Do not offer fruit, leafy greens, commercial "reptile salad" mixes, or any plant-based food. Even the occasional grape or berry, often recommended in outdated care guides, contributes sugar and water with no nutritional benefit and can disrupt gut microbiome balance.

Best Feeder Insects

Crickets

Crickets are the most widely available feeder insect and form the basis of most leopard gecko diets. They are nutritionally balanced, stimulate natural hunting behavior, and are accepted by virtually all leopard geckos. Use appropriately sized crickets only — no wider than the space between the gecko's eyes. Crickets left overnight in the enclosure can bite a sleeping gecko; remove uneaten crickets after 20 minutes.

Dubia Roaches

Dubia roaches (Blaptica dubia) are nutritionally superior to crickets — higher in protein, lower in chitin (the indigestible shell component), and easier to digest. They do not jump or chirp. Many experienced keepers consider dubias the ideal staple feeder. They are not legal in all states or countries, so check local regulations.

Mealworms

Mealworms are a popular and convenient feeder. They have a higher fat content than crickets or roaches, so they are best used as a supplemental food rather than a daily staple — particularly for adult geckos prone to weight gain. Mealworms are excellent for the bowl method (see below).

Waxworms: Treats Only

Waxworms are the candy of the gecko world: extremely palatable, extremely fatty (up to 23% fat), and almost addictive. A gecko fed too many waxworms will often refuse less fatty foods. Limit waxworms to 1–2 per week maximum as an occasional treat, or use them to entice a sick or underweight gecko to eat.

Insects to Avoid

• Wild-caught insects: May carry pesticides, parasites, or herbicide residue
• Fireflies (lightning bugs): Toxic to reptiles — potentially fatal even in small amounts
• Any insect from outside: Unknown pesticide exposure

Gut-Loading: What You Feed the Insect, You Feed the Gecko

Feeder insects are nutritionally what they eat. Crickets raised on cardboard egg cartons and given no food offer almost nothing to your gecko. Gut-load all feeder insects for at least 24 hours before offering them, ideally 48 hours.

Good gut-load foods include: collard greens, dandelion greens, butternut squash, sweet potato, and commercial gut-load products. Avoid citrus, spinach (high oxalates), and iceberg lettuce (almost zero nutrition). A well gut-loaded insect is visibly fuller and has a slightly distended abdomen.

For a convenient gut-load solution, Zooplus stocks live feeder insects and gut-load formulas appropriate for insectivorous reptiles like leopard geckos.

Calcium and D3 Supplementation

Supplementation is not optional — it is essential. Feeder insects have a poor calcium-to-phosphorus ratio, and without calcium supplementation, leopard geckos develop metabolic bone disease (MBD), a painful and often irreversible condition that weakens bones and deforms the jaw.

Use two supplements:

• Calcium without D3: Dust insects lightly at every feeding for hatchlings and juveniles. Adults: every other feeding.
• Calcium with D3 (or a multivitamin): Once or twice per week. D3 is required for calcium absorption. Leopard geckos in captivity receive little UVB light and cannot synthesize D3 naturally.

The dusting technique: put supplement powder in a small container, drop in the insects, shake gently, and offer immediately. Insects lose the powder within minutes, so do not pre-dust and wait.

Feeding by Age: Schedule Chart

Prey size rule: never offer an insect wider than the space between the gecko's eyes. Oversized prey causes regurgitation and in rare cases can contribute to neurological issues.

The Mealworm Bowl Method for Adults

Many adult keepers use a small, smooth-sided bowl (a ramekin works perfectly) filled with mealworms left in the enclosure. The gecko visits the bowl to feed at will, simulating ad-lib grazing behavior. This works well because adult geckos self-regulate reasonably well, and mealworms cannot climb the smooth sides to escape and hide in the substrate. Do not use this method as the sole food source — rotate in crickets or roaches regularly for variety and enrichment.

Signs of a Healthy vs. Undernourished Gecko

The leopard gecko's tail is its fat reserve. A healthy, well-fed gecko has a tail as wide as or wider than its body at the base. A thin, carrot-shaped or pencil-thin tail signals insufficient food intake or illness. A tail that is excessively wide and lumpy may indicate obesity from too many fatty feeders.

Other signs of good condition: alert and reactive behavior during active hours, clean bright eyes, willingness to hunt, no retained shed on toes or around eyes.

A Note on Calcium Sand: Do Not Use It

Despite the name, calcium sand is dangerous for leopard geckos. Ingested deliberately (a behavior called geophagy, often driven by calcium deficiency) or accidentally during feeding, it can compact in the digestive tract causing fatal impaction. Use tile, reptile carpet, or paper towels as substrate. If you want a natural-looking enclosure, slate tile or non-adhesive shelf liner are safe and easy to clean.

Water

Always provide a small, shallow water dish with clean water. Leopard geckos drink more than many keepers expect, particularly during shedding. Change water every 1–2 days and scrub the dish weekly to prevent bacterial buildup.