Doxycycline

ID: doxycycline

Aliases: subantimicrobial-dose doxycycline, SD doxycycline

Type: compound

Route/form: oral

Status: approved_drug

Evidence level: human RCT

Best data tier: human controlled/review

Support scope: human

Source types: human_rct

Linked sources: 2

Broad outcomes: Brain / mood / sleep, Gut / immune / inflammation, Skin / wound repair

Reading note: These are curation notes anchored to linked sources, not a clinical recommendation or protocol.

Targets / mechanism

• tetracycline antibiotic activity
• matrix metalloproteinase modulation
• neuroplasticity hypothesis

Optimization domains

• skin health
• acne
• mental acuity
• antimicrobial stewardship

Research basis

• Human work includes subantimicrobial-dose acne evidence and a randomized study reporting improved declarative learning and memory in healthy humans.
• Useful example of an approved drug with non-obvious CNS and dermatology discussions.

Limits, risks, and missing evidence

• Cognition use is off-label and needs replication, mechanism clarity, and risk/benefit review.
• Antibiotic adverse effects, photosensitivity, microbiome effects, pregnancy restrictions, and resistance stewardship matter even when low-dose strategies are discussed.

Risk flags

• prescription drug
• antibiotic stewardship
• photosensitivity
• microbiome
• pregnancy contraindication
• medical supervision

Linked papers, labels, and reviews

1. Forget me not: the effect of doxycycline on human declarative memory
   human_rct / sciencedirect_doxycycline_declarative_memory_2024
   Healthy-human declarative learning and memory study.
2. Effects of subantimicrobial-dose doxycycline in moderate acne
   human_rct / jama_subantimicrobial_doxy_acne_2003
   Moderate acne trial assessing lesions, skin flora, and resistant organisms.