Doxycycline isn’t just an antibiotic; at low doses it tones down inflammation and blocks matrix-metalloproteinases (MMPs), enzymes that may be overactive in Long COVID and ME/CFS. One hypothesis argues that dialing back MMPs could stabilize connective tissue, calm neuro-inflammation, and raise the dreaded post-exertional-malaise (PEM) threshold.

Research Snapshot

• Zero randomized trials have tested doxy in Long COVID or ME/CFS.

• Small studies in acute COVID show MMP-inhibition may blunt disease severity, hinting at a downstream benefit for post-viral syndromes.

• Everything else comes from patient-led proposals and mechanistic papers on MMPs and neuro-inflammation.

Real-World Stories (Crowdsourced from X & Forums)

• “Next-morning turnaround.” A severe long-hauler said one dose melted crushing fatigue and pain.

• PEM buffer. After three weeks, another user could exceed previous activity limits without crashing—calling it “actual magic.”

• Mixed bag. Others felt nothing, or stopped after GI upset or photosensitivity. No pattern yet; responses are wildly individual.

Add Your Experience 💬

Because the evidence gap is huge, patient reviews are gold for others weighing the same decision.

1. Scroll to the “Add Review” box at the top.

2. Tell us your dose, duration, what changed (or didn’t), and any side-effects.

3. Hit "Post" —whether doxy was a game-changer, a dud, or something in between. You can add your review anonymously.

Each story sharpens the community’s compass and nudges researchers to pay attention. Thanks for lending your voice and helping all of us move one step closer to answers.