Why One Dose of Doxycycline After a Tick Bite Isn’t Enough - What the research really says, and what patients need to know

It’s tick season, and if you’ve ever been bitten, you’ve probably heard this advice: “Just take one 200 mg dose of doxycycline and you’ll be fine.”

This recommendation has become a common “quick fix” in emergency rooms and urgent care centers across the country. But is it based on solid science? Unfortunately, no.

Let’s break down the origin of this recommendation—and why it’s long overdue for a serious update.

Where Did This Come From?

The advice to take a single 200 mg dose of doxycycline after a tick bite comes from one single randomized controlled trial (RCT) published in 2001 by Nadelman et al. in the New England Journal of Medicine. Source

Here’s what the study actually involved:

• Only 8 people in the treatment group met the inclusion criteria

• The tick had to be attached for 36+ hours

• Participants were given a one-time dose of 200 mg doxycycline

• Follow-up lasted just 6 weeks

• The endpoint was the development of a skin lesion, not lab-confirmed Lyme disease

• There was no long-term follow-up to rule out late-stage Lyme

That’s it. One small, narrow study with serious limitations—yet it has shaped mainstream treatment protocols for more than two decades.

Why This Is a Problem

According to a critical analysis published

Wood Tick 6/2025

n the Journal of the American Pharmacists Association (2015), the study had several glaring flaws:

• Sample size was too small to draw meaningful conclusions

• Follow-up was insufficient to detect late or chronic Lyme

• The endpoint was unvalidated, based solely on the absence of rash—not full Lyme disease testing or symptom tracking

• No generalizability to children, immunocompromised patients, or different tick species

The authors of that review stated:

“It is impossible to state a meaningful success rate for the prevention of Lyme disease by a single 200 mg dose of doxycycline because the sole trial of that regimen utilized an inadequate observation period and unvalidated surrogate endpoint.”

The Risk of Under-Treatment

Lyme disease is a complex, systemic infection. If not treated early and thoroughly, it can lead to long-term symptoms such as fatigue, joint pain, brain fog, and even neurological conditions like POTS (Postural Orthostatic Tachycardia Syndrome).

A single dose of doxycycline may reduce the chance of early Lyme rash—but it does not prevent infection, and it certainly doesn’t address the risk of other tick-borne infections like Bartonella, Babesia, Ehrlichia, or Anaplasma.

What’s worse? Inadequate treatment may lead to seronegative Lyme, where immune suppression or early antibiotic use alters the body’s antibody response—leading to false-negative tests later on.

What Patients Deserve: Real Prevention and Thoughtful Treatment

If you’ve been bitten by a tick, here’s what you need to know:

✅ Save the tick and send it for testing through a reliable lab like TickReport or TickCheck

✅ Minimum of 21 days of doxycycline (100 mg twice daily) is recommended for known tick bites, especially in endemic areas ILADS Guidelines. *Note: Evelyn does not prescribe doxycycline during the summer months due to sun sensitivity - we advise you recommend discussion alternate antibiotics with your prescriber

✅ Longer treatment is needed if symptoms develop or persist

✅ Always pair antibiotics with a high-quality probiotic, such as Ortho Biotic by Ortho Molecular, to protect the gut microbiome

✅ Seek out a Lyme-literate provider who understands the nuances of tick-borne illness and won’t dismiss lingering symptoms

The Bottom Line

It’s time to move beyond outdated, one-size-fits-all protocols. Lyme disease is real. Complex. And it deserves more than a single pill and a 6-week follow-up phone call.

Let’s demand better care, better research, and better outcomes.