Bearded Dragon Diet: What to Feed (and What to Avoid)

Diet is one of the most common sources of health problems we see in bearded dragons at our Alhambra clinic. Not because owners don't care — but because there's a lot of conflicting information out there, and the needs of a juvenile dragon are genuinely different from those of an adult. Getting this right from the start makes a real difference in long-term health and lifespan.

Here's a practical, accurate guide to what bearded dragons eat, how that changes as they grow, what to supplement, and what to avoid entirely.

How Diet Changes With Age

This is the most important thing to understand about bearded dragon nutrition. A juvenile dragon has completely different needs than an adult:

• Juveniles (0–12 months): 60–70% insects, 30–40% vegetables. Young dragons grow rapidly and need protein to support that growth. Offer insects 2–3 times daily; fresh greens should always be available but are primarily supplemental at this stage.
• Sub-adults (12–18 months): Gradually shift toward 50/50. Begin reducing daily insect feedings to once daily.
• Adults (18+ months): 70–80% vegetables, 20–30% insects. Excessive protein in adult dragons is associated with kidney damage and gout. Insects 3–4 times weekly; fresh greens available every day.

One of the most common diet mistakes we see is continuing to feed adult dragons as if they were juveniles — daily insects and minimal vegetables. Over time, this contributes to kidney problems and obesity.

Best Feeder Insects

Not all insects are equal in nutrition. Here are the best options:

Dubia Roaches

The gold standard for bearded dragon nutrition. Dubias have an excellent protein content, high moisture, a reasonable calcium-to-phosphorus ratio, and produce minimal waste compared to crickets. They don't jump, can't climb smooth surfaces, and don't make noise. If you can only offer one insect type, dubias are the best choice. Note: they are prohibited as a feeder insect in a small number of states; they are legal in California.

Crickets

The most widely available feeder insect. Nutritionally acceptable when gut-loaded (fed a nutritious diet for 24–48 hours before offering to the dragon). They smell, escape easily, can bite sleeping dragons, and die quickly, but they're fine when managed carefully. Never leave live crickets loose in the enclosure overnight.

Black Soldier Fly Larvae (Calci-worms / Phoenix Worms)

High in calcium — one of the few insects with a favorable calcium-to-phosphorus ratio without extra dusting. Good as a supplemental feeder. Soft-bodied and easy for dragons of all ages to eat.

Hornworms and Silkworms

Both are high in moisture and good as treats or for encouraging a dragon that's off food. Hornworms are high in water content (which makes them a poor staple for hydration-sensitive dragons); silkworms are soft, nutritious, and well-accepted.

Mealworms and Waxworms

High in fat. Fine as occasional treats for adults. Should not be fed as a staple and are not recommended for juveniles at all due to their hard chitin content (impaction risk for small dragons).

Insects to Avoid Entirely

• Fireflies (lightning bugs). Toxic to bearded dragons — even a single firefly can be fatal. Never feed these.
• Wild-caught insects. Risk of pesticide exposure and unknown parasites.
• Insects larger than the space between the dragon's eyes. Risk of impaction and choking.

Gut-Loading: Why It Matters

Insects themselves are not particularly nutritious. The nutrition a bearded dragon gets from an insect is largely the nutrition that insect consumed before being fed to the dragon — this is called gut-loading. Crickets or roaches purchased from a pet store and fed immediately are essentially empty calories.

Good gut-load foods: collard greens, mustard greens, dandelion greens, squash, sweet potato, bell pepper, and commercial gut-load products. Feed insects 24–48 hours before offering them to your dragon.

Best Vegetables and Greens

These should be available to adult dragons every day and to juveniles as a supplement:

• Collard greens — excellent calcium source, available year-round
• Mustard greens — high in vitamins A and K
• Dandelion greens — high in calcium; the whole dandelion plant (leaves and flowers) is fine if pesticide-free
• Arugula — good nutritional profile, most dragons accept it readily
• Turnip greens — good calcium source
• Butternut squash and acorn squash — good source of beta-carotene; offer raw or lightly cooked
• Bell pepper (red or yellow) — high in vitamin C; most dragons love it
• Snap peas — acceptable in moderation

Vegetables to Limit or Avoid

• Spinach. Binds calcium and should not be a staple. Occasional small amounts are fine.
• Iceberg lettuce. Almost zero nutritional value; mostly water. Use it only as a hydration tool, not a food.
• Beet greens and Swiss chard. High in oxalates; limit use.
• Avocado, rhubarb, onion, garlic. Toxic to bearded dragons. Never feed these.
• Wild plants you can't identify. Risk of toxicity.

Fruit

Fruit can be offered as an occasional treat (once or twice weekly) but should not be a staple. High sugar content can contribute to obesity and loose stools. Good options in small amounts: blueberries, raspberries, mango, papaya, melon. Avoid grapes and raisins; citrus causes digestive upset in some dragons.

Calcium and Vitamin Supplementation

This is non-negotiable. Most feeder insects have a poor calcium-to-phosphorus ratio (high in phosphorus, low in calcium). Without supplementation, calcium deficiency leads to metabolic bone disease — one of the most preventable yet common causes of death in captive bearded dragons.

The standard supplementation protocol:

• Calcium powder (without D3): dust insects 5 days per week
• Calcium with D3 or reptile multivitamin: 2 days per week

Do not use D3 daily — vitamin D3 is fat-soluble and can accumulate to toxic levels with excessive supplementation. If your UVB lighting is optimal, you can reduce D3 supplementation frequency, but discuss this with a reptile vet.

Water

Bearded dragons get much of their hydration from the fresh vegetables they eat. However, a shallow water dish should be available in the enclosure — some dragons drink from standing water. Bathing your dragon in shallow warm water for 15–20 minutes 2–3 times weekly also provides hydration and supports shedding. Make sure bath water is not too deep and never leave the dragon unattended.

Signs of a Diet Problem

Common signs that something is off with the diet include:

• Muscle tremors or weakness in the limbs (often metabolic bone disease — calcium/vitamin D deficiency)
• Swollen or soft jaw or limbs (MBD)
• Persistent refusal to eat vegetables (especially in adults)
• Obesity (fat deposits along the sides, heavy tail base)
• Persistent loose or discolored stool (parasites, too much fruit or high-water foods)
• Lethargy not explained by temperature or brumation

If you're seeing any of these, a vet visit is the right move. Many diet-related problems are very correctable when caught before they become advanced. We see bearded dragons at South Pasadena Animal Hospital in Alhambra — check our pricing page for visit costs.

Frequently Asked Questions

What do bearded dragons eat?

A combination of live insects and fresh vegetables. Juveniles eat primarily insects (60–70%); adults eat primarily vegetables (70–80%). All insects should be gut-loaded and dusted with calcium supplement before feeding.

What vegetables are safe for bearded dragons?

Best choices: collard greens, mustard greens, dandelion greens, arugula, turnip greens, butternut squash, bell pepper. Avoid spinach as a staple, and never feed avocado, rhubarb, or anything in the onion family.

What insects can bearded dragons eat?

Best: dubia roaches, crickets, black soldier fly larvae. Good treats: hornworms, silkworms. Avoid: fireflies (toxic), wild-caught insects, and insects larger than the space between the dragon's eyes.

How often should I feed my bearded dragon?

Juveniles: insects 2–3 times daily; greens always available. Adults: insects 3–4 times per week; fresh greens daily. Overfeeding insects to adults contributes to kidney problems over time.

Do bearded dragons need calcium supplements?

Absolutely. Dust insects with calcium powder (no D3) 5 days per week, and with a D3 or multivitamin supplement 2 days per week. Without supplementation, metabolic bone disease is likely to develop over time.