5 Best UVB Lights for Bearded Dragons (2026 Reviews)
Expert-tested UVB lights for bearded dragons. Comparing T5 HO tubes, mercury vapor, and combo fixtures.
Last updated: February 9, 2026
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Our Top Picks
Arcadia ProT5 Kit 12% Desert UVB
The Arcadia 12% Desert T5 HO is widely considered the best UVB solution for bearded dragons by experienced keepers and veterinarians alike. It produces strong, consistent UVB output across a wide coverage area, with a 12-month replacement cycle (versus 6 months for competitors). The ProT5 kit includes a quality reflector that maximizes output. This is the UVB light that breeders and reptile veterinarians recommend most frequently.
Pros
- +Industry-leading UVB output consistency
- +12-month replacement cycle (saves money long-term)
- +Excellent reflector included in kit
- +Trusted by breeders and reptile vets worldwide
Cons
- -Higher upfront cost than Zoo Med
- -Less widely available in US pet stores
- -Requires separate basking bulb for heat
Zoo Med ReptiSun 10.0 T5 HO UVB
The Zoo Med ReptiSun 10.0 T5 HO is the most popular UVB tube in North America. It's available at virtually every pet store, produces reliable UVB output, and fits standard T5 HO fixtures. The main drawback compared to Arcadia is the 6-month replacement cycle, which means you'll buy twice as many bulbs over time. Still an excellent choice, especially for keepers who want easy local availability.
Pros
- +Available at almost every pet store
- +Reliable, proven UVB output
- +Lower upfront cost
- +Wide range of lengths available
Cons
- -6-month replacement cycle (vs 12 for Arcadia)
- -Must buy separate reflector fixture
- -Slightly less consistent output in testing
Mega-Ray Mercury Vapor Bulb 160W
The Mega-Ray is a mercury vapor bulb (MVB) that combines UVB, UVA, visible light, and heat in a single bulb. This is convenient for keepers who want an all-in-one solution without managing separate basking and UVB fixtures. The 160W version is appropriate for 120-gallon bearded dragon enclosures. Note that MVBs produce a focused beam rather than broad coverage, so they work best when paired with a secondary UVB source or positioned carefully.
Pros
- +All-in-one: UVB + UVA + heat + visible light
- +Strong UVB output at proper distance
- +Simulates natural sunlight more closely
- +Good for open-top enclosures
Cons
- -Cannot be used with a dimmer/thermostat (fixed wattage)
- -Focused beam — less even coverage than linear tubes
- -Runs hot — not suitable for small enclosures
- -Bulky — needs a deep dome fixture
Arcadia ShadeDweller ProT5 Kit 7% UVB
The ShadeDweller 7% is Arcadia's lower-output option designed for crepuscular and shade-dwelling species. While it's excellent for leopard geckos and crested geckos, it does NOT provide sufficient UVB for bearded dragons. We're including it here as a warning — many new keepers accidentally buy the ShadeDweller (7%) when they need the Desert (12%). For bearded dragons, always choose the 12% Desert version.
Pros
- +Excellent for leopard geckos and cresteds
- +Same quality build as Desert version
- +Good supplemental option for shaded areas
Cons
- -NOT strong enough for bearded dragons
- -Commonly purchased by mistake
- -Only suitable for low-UVB species
Zoo Med T5 HO Reptile Hood Fixture
Not a bulb but an essential accessory — this is the fixture you need if you buy a standalone Zoo Med ReptiSun 10.0 tube. It includes a built-in reflector (critical for maximizing UVB output), mounting hardware, and accepts standard T5 HO tubes in various lengths. If you already have a ReptiSun tube, this is the fixture to pair it with. Also compatible with Arcadia T5 tubes.
Pros
- +Built-in reflector maximizes UVB output
- +Universal T5 HO compatibility
- +Easy mounting options
- +Affordable
Cons
- -Plastic construction feels cheap
- -Reflector quality below Arcadia ProT5 kit
- -Must buy tube separately
Why UVB Lighting Is Non-Negotiable for Bearded Dragons
UVB light enables bearded dragons to synthesize vitamin D3 in their skin. Without D3, they cannot absorb calcium from their diet — leading directly to metabolic bone disease (MBD), one of the most common and devastating health problems in captive reptiles.
No amount of calcium supplementation fully replaces proper UVB exposure. While calcium with D3 powder helps, studies show that UVB-derived D3 is regulated more effectively by the reptile's body than dietary D3. In short: UVB is not optional.
For complete care information, see our bearded dragon care guide and tank setup guide.
Types of UVB Lights Explained
T5 HO Linear Fluorescent Tubes (Recommended)
T5 HO (High Output) linear tubes are the standard recommendation for bearded dragons. They provide:
- Broad, even coverage across 2/3 of the enclosure
- Consistent output across the tube length
- Predictable decay — output decreases gradually, making replacement schedules reliable
- Variety of strengths — 5%, 7%, 10%, 12% options for different species
For bearded dragons, use a 10% (Zoo Med ReptiSun 10.0) or 12% (Arcadia Desert) tube that spans approximately 2/3 of the enclosure length.
Mercury Vapor Bulbs (MVBs)
Mercury vapor bulbs combine UVB, UVA, visible light, and heat in a single screw-in bulb. They're convenient but have limitations:
- Focused beam — good coverage directly underneath, but poor to the sides
- Cannot be dimmed — fixed wattage, so they're harder to integrate with thermostats
- Better for large, open enclosures where the focused beam is positioned over the basking spot
MVBs work well as a basking + UVB combo over a single basking zone, but most keepers still recommend a linear T5 tube for primary UVB coverage.
Compact/Coil UVB Bulbs (NOT Recommended)
Compact UVB bulbs screw into standard fixtures and are sold in many starter kits. Do not use these for bearded dragons. Their coverage area is too small (6-8 inch radius), UVB output drops off sharply with distance, and early versions were linked to eye damage. Always use a linear T5 HO tube or MVB instead.
How to Set Up UVB Properly
Mounting Position
The UVB tube should run along the same side as your basking light, covering approximately 2/3 of the enclosure length. This creates a UVB gradient — strong exposure at the basking end, decreasing toward the cool side — that lets your bearded dragon self-regulate its UV exposure.
Distance Guidelines
| UVB Tube | With Mesh Screen | Without Screen (Inside Mount) |
|---|---|---|
| Arcadia 12% T5 HO | 12-15 inches from basking spot | 15-18 inches |
| Zoo Med ReptiSun 10.0 T5 HO | 10-12 inches | 12-15 inches |
Important: Mesh screens block 30-40% of UVB output. If your enclosure has a screen top, either mount the UVB inside the enclosure (with a protective cage/guard) or account for the loss by positioning the bulb closer.
Reflector Importance
A good reflector can nearly double the UVB output reaching your bearded dragon. The Arcadia ProT5 kit includes an excellent reflector. If using a standalone Zoo Med tube, pair it with the Zoo Med T5 HO fixture (which includes a reflector) — never mount a bare tube without a reflector.
Replacement Schedule
UVB bulbs continue producing visible light long after their UVB output has decayed below useful levels. You cannot tell if a UVB bulb is still effective by looking at it. Stick to the manufacturer's replacement schedule:
- Zoo Med ReptiSun 10.0 T5 HO: Replace every 6 months
- Arcadia 12% Desert T5 HO: Replace every 12 months
- Mega-Ray MVB: Replace every 6-12 months (test with a Solarmeter if available)
Mark the installation date on the bulb with a permanent marker so you don't forget.
UVB Testing: Solarmeters
For keepers who want precision, a Solarmeter 6.5R measures UVB output in microwatts per square centimeter. This lets you verify that your bulb is still producing adequate UVB and that your mounting distance is correct.
- Target UVB at basking spot: 150-250 µW/cm² (Ferguson Zone 3-4 for bearded dragons)
- Cost: ~$250 for the meter
A Solarmeter is not required for casual keepers, but it's a worthwhile investment if you keep multiple reptiles or breed.
Common UVB Mistakes
- Using compact/coil UVB — insufficient coverage for bearded dragons
- Not replacing on schedule — the bulb looks fine but produces no useful UVB
- Mounting too far away — UVB intensity drops exponentially with distance
- No reflector — wastes up to 50% of UVB output
- UVB on 24/7 — should follow the same photoperiod as basking light (10-14 hours)
- Blocking with glass/plastic — glass and most plastics block 100% of UVB. Only wire mesh is acceptable between bulb and reptile
Frequently Asked Questions
How long should I leave the UVB light on for my bearded dragon?
UVB should be on for 10-14 hours per day, matching the basking light photoperiod. In summer, aim for 14 hours on / 10 hours off. In winter, 10 hours on / 14 hours off. Use a timer to automate the cycle consistently.
Can I use a UVB light without a basking light?
No. UVB and basking heat serve different functions and both are necessary. UVB enables vitamin D3 synthesis, while basking heat is needed for digestion, thermoregulation, and actually activating D3 conversion. You need both.
Do bearded dragons need UVB at night?
No. Turn off all lights (UVB and basking) at night to simulate a natural day/night cycle. Bearded dragons need complete darkness to sleep properly. If supplemental nighttime heat is needed, use a ceramic heat emitter which produces heat without light.
Is the Arcadia 12% really worth the extra cost over Zoo Med?
Yes, in the long run. The Arcadia 12% costs more upfront but lasts 12 months versus 6 months for Zoo Med. Over 2 years, you'll buy 2 Arcadia bulbs versus 4 Zoo Med bulbs, making total cost roughly equal — while getting more consistent UVB output throughout the bulb's life.
Final Verdict
The Arcadia ProT5 12% Desert Kit is our top recommendation for bearded dragon UVB lighting. Its 12-month replacement cycle, superior reflector, and consistent output make it the best long-term value. If availability or upfront budget is a concern, the Zoo Med ReptiSun 10.0 T5 HO paired with the Zoo Med T5 fixture is an excellent alternative used successfully by millions of bearded dragon keepers.
Whichever brand you choose, the key is using a linear T5 HO tube at the correct distance with a reflector — that combination will keep your bearded dragon healthy for years to come.