VarroxSan Oxalic Acid Extended-Release Varroa Mite Treatment

VarroxSan is an EPA-registered extended-release Varroa mite treatment containing 18.42% oxalic acid dihydrate in specially designed fiberboard strips. As bees move across and interact with the strips, oxalic acid is gradually distributed throughout the colony, providing continuous mite control without requiring repeated applications throughout the treatment period.

Independent U.S. and international trials have reported an average efficacy of 98.6% when VarroxSan is used according to the label, making it a powerful option for beekeepers looking for effective, straightforward Varroa management.

Why We Like VarroxSan

Traditional oxalic acid treatments can require careful timing or multiple applications, particularly when brood is present. VarroxSan takes a different approach.

The extended-release strips remain inside the colony for 42–56 days, allowing bees to continually interact with the treatment over an extended period.

That means less opening of the hive, fewer individual treatment applications, and a simple way to incorporate oxalic acid into your Varroa management program.

Key Benefits

• 98.6% average efficacy reported across independent trials when used according to the label
• Provides 42–56 days of extended oxalic acid release
• No temperature restrictions, giving beekeepers greater flexibility throughout the season
• Approved for use with honey supers present according to the product label
• Designed for use with brood present
• No repeated applications required during the treatment period
• Can be incorporated into spring, summer, or fall Varroa management
• No known Varroa resistance to oxalic acid
• Suitable for organic beekeeping programs where permitted
• Straightforward strip application and removal

How to Apply VarroxSan

Placement matters because the bees need to interact with the strips for the treatment to work effectively.

For a standard deep brood chamber, use up to 4 strips, placing them between brood frames where bees will regularly walk across them.

Leave the strips in place for 42–56 days, then remove them. Do not leave VarroxSan in the hive longer than 56 days.

If the bees are no longer contacting the strips after 42 days, reposition them closer to the cluster according to the label.

For colonies using two deep brood chambers, place 4 strips in the lower brood chamber, with up to 2 additional strips in the upper chamber when it is fully occupied by bees.

Medium brood chambers require different dosing. Follow the current product label for the correct number and placement of strips for your hive configuration.

When to Use VarroxSan

VarroxSan can be used throughout the beekeeping season when applied according to its label, making it especially useful when other treatment options are limited by temperature or management conditions.

We always recommend making Varroa decisions based on actual mite counts rather than the calendar alone.

Test your colony before treatment so you know your starting mite pressure, apply VarroxSan according to the label, and test again after treatment to determine how effectively your mite population was reduced.

Treatment is only half the equation. Knowing whether it worked is what protects your bees.

Available Sizes

20 strips
Treats approximately 5–10 colonies*

60 strips
Treats approximately 15–30 colonies*

600 strips
10 × 60-strip packs, ideal for larger apiaries and commercial operations*

*The number of colonies treated depends on hive configuration and label-directed dosing.

VarroxSan can now be shipped to California.

Storage & Shelf Life

Store VarroxSan below 86°F (30°C) and protect it from direct sunlight.

Do not refrigerate or freeze.

Shelf life: 24 months from the date of manufacture.

Protect the Bees That Carry Your Colony Forward

Varroa management isn’t simply about reducing the number of mites you see today. Especially in late summer and fall, keeping mite pressure under control helps protect the developing bees your colony will depend on through winter.

Test. Treat. Verify. Keep Your Hive Alive.

Always read and follow the current VarroxSan product label, including application rate, placement, treatment duration, personal protective equipment, and other use requirements.