Doxycycline vs Doxycycline Hyclate: side effects in FDA adverse event reports
At a glance
| Doxycycline | Doxycycline Hyclate | |
|---|---|---|
| Drug class | Tetracycline-class Drug | – |
| Brand names | – | – |
| FAERS reports | 67,795 | 67,065 |
| Serious | 72% | 73% |
| Death outcome | 6,693 | 6,708 |
| Boxed warning | No | No |
Signals both drugs share
| Reaction | Doxycycline | Doxycycline Hyclate | Label screen (A / B) |
|---|---|---|---|
| Sleep disorder due to general medical condition, insomnia type | 892 · PRR 49.6 | 893 · PRR 50.3 | Labeled (related wording) / Labeled (related wording) |
| Autoimmune disorder | 890 · PRR 31.6 | 890 · PRR 32.0 | Labeled (related wording) / Not in label — unassessed |
| Jarisch-herxheimer reaction | 309 · PRR 237.3 | 312 · PRR 244.0 | Not in label — unassessed / Labeled adverse reaction |
| Subcutaneous drug absorption impaired | 50 · PRR 31.2 | 50 · PRR 31.5 | Not in label — unassessed / Labeled (related wording) |
| Helicobacter infection | 1,281 · PRR 44.4 | 1,281 · PRR 44.8 | Not in label — unassessed / Not in label — unassessed |
| Hand deformity | 1,271 · PRR 33.2 | 1,271 · PRR 33.6 | Not in label — unassessed / Not in label — unassessed |
| Duodenal ulcer perforation | 1,219 · PRR 61.5 | 1,219 · PRR 62.2 | Not in label — unassessed / Not in label — unassessed |
| Folliculitis | 1,200 · PRR 40.6 | 1,200 · PRR 41.0 | Not in label — unassessed / Not in label — unassessed |
| Rheumatic fever | 1,095 · PRR 103.5 | 1,095 · PRR 104.6 | Not in label — unassessed / Not in label — unassessed |
| Muscle injury | 872 · PRR 36.7 | 872 · PRR 37.1 | Not in label — unassessed / Not in label — unassessed |
| Deep vein thrombosis postoperative | 869 · PRR 247.6 | 869 · PRR 250.3 | Not in label — unassessed / Not in label — unassessed |
| Lip dry | 792 · PRR 29.9 | 793 · PRR 30.3 | Not in label — unassessed / Not in label — unassessed |
| Facet joint syndrome | 710 · PRR 89.9 | 710 · PRR 90.9 | Not in label — unassessed / Not in label — unassessed |
| Abortion incomplete | 553 · PRR 128.4 | 553 · PRR 129.7 | Not in label — unassessed / Not in label — unassessed |
| Bone erosion | 510 · PRR 51.9 | 510 · PRR 52.5 | Not in label — unassessed / Not in label — unassessed |
| Adjustment disorder with depressed mood | 510 · PRR 104.8 | 510 · PRR 105.9 | Not in label — unassessed / Not in label — unassessed |
| Lupus vulgaris | 509 · PRR 232.4 | 509 · PRR 234.9 | Not in label — unassessed / Not in label — unassessed |
| Dislocation of vertebra | 456 · PRR 79.7 | 456 · PRR 80.6 | Not in label — unassessed / Not in label — unassessed |
| Retinitis | 409 · PRR 100.4 | 409 · PRR 101.5 | Not in label — unassessed / Not in label — unassessed |
| Nephrogenic anaemia | 405 · PRR 29.3 | 403 · PRR 29.4 | Not in label — unassessed / Not in label — unassessed |
Labeled signals distinctive to Doxycycline
- None stood out among the strongest labeled signals.
Labeled signals distinctive to Doxycycline Hyclate
- None stood out among the strongest labeled signals.
Common questions
Which has more reported side effects, Doxycycline or Doxycycline Hyclate?
Doxycycline has 67,795 FAERS reports and Doxycycline Hyclate 67,065. More reports does not mean more dangerous: volume follows how widely and how long a drug has been used, prescription vs over-the-counter status, and publicity. The seriousness share (72% vs 73%) is a better like-for-like signal of the kind of problems reported.
Which side effects do Doxycycline and Doxycycline Hyclate share?
Both drugs carry disproportionality signals for sleep disorder due to general medical condition, insomnia type, autoimmune disorder, jarisch-herxheimer reaction, subcutaneous drug absorption impaired, helicobacter infection. Shared signals often reflect a shared drug class or the condition both are used for.
Is Doxycycline or Doxycycline Hyclate safer?
FAERS cannot answer that: it has no denominator and no comparator. Use this page to see which risks are already on each label and which signals are unlabeled, then check the prescribing information and your clinician for your situation.
Sources: openFDA FAERS pair statistics (OpenPV build 2026-09-14), FDA labels via openFDA, openFDA count queries for seriousness and deaths. Pair chosen because it is a commonly searched comparison. Generated 2026-10-08.