Microdosing GLP-1 for Health & Longevity - Quick Reference Sheet

Microdosing GLP-1 for Health & Longevity

Created on 09/22/2026 – Quick Reference based on Evidence Review created using AI4L / Opus 5 – Audit

Microdosing GLP-1 uses the prescription medications for diabetes and weight reduction at or below the lowest amount used for long-term treatment, rather than raising it until appetite is strongly suppressed. Blood sugar, blood pressure and the main blood marker of low-grade inflammation improve; fat loss is partial. Unwanted effects also scale with the amount. No study has followed low-dose use beyond a few years. (Full Review)

Protocol

Semaglutide microdose range
0.125–0.5 mg weekly
Subcutaneous, against 2.4 mg for weight reduction. No trial data exist below 0.25 mg.
Tirzepatide microdose range
0.5–2.5 mg weekly
Subcutaneous, against 10–15 mg for weight reduction. Somewhat better lean-mass preservation per kilogram lost.
Oral semaglutide alternative
3 mg daily
Or a 3 mg tablet 2–3 times weekly. Requires dosing fasted with no more than 120 mL water and a 30-minute wait before food.
Time to effect
Glycaemic markers
8–12 weeks
Fasting glucose and HbA1c begin to move.
C-reactive protein
~12 weeks
The blood marker of low-grade inflammation.
Body composition
3–6 months
Change becomes measurable.

Benefits

Contraindications
  • Personal or family history of medullary thyroid carcinoma, or multiple endocrine neoplasia type 2
  • Prior episode of acute or chronic pancreatitis
  • Established gastroparesis or any diagnosed gastric-emptying disorder
  • Pregnancy, attempted conception within 2 months, or breastfeeding
  • Active proliferative diabetic retinopathy, or non-proliferative retinopathy with HbA1c above 9%, until ophthalmological review
  • Body mass index below 18.5 kg/m², or any current or past restrictive eating disorder
  • Severe hepatic impairment (Child-Pugh Class C) or eGFR below 15 mL/min/1.73 m²
  • Type 1 diabetes without specialist supervision
Key Interactions
  • Insulin and sulfonylureas (glipizide, glyburide, glimepiride)
  • Narrow-therapeutic-index oral medications (levothyroxine, warfarin, digoxin, lithium)
  • Oral contraceptives (ethinylestradiol-levonorgestrel, norethisterone)
  • Opioids (oxycodone, codeine, loperamide) and anticholinergics (oxybutynin, amitriptyline, diphenhydramine)
  • Dipeptidyl peptidase-4 inhibitors (sitagliptin, linagliptin)
  • Sodium-glucose cotransporter-2 inhibitors (empagliflozin, dapagliflozin)
  • Glucose-lowering supplements (berberine, bitter melon, chromium picolinate, cinnamon extract, alpha-lipoic acid)
  • Viscous fibre supplements (psyllium, glucomannan)
  • Iron supplements
  • Alcohol
  • Other weight-directed interventions (very-low-calorie diets, extended fasting, stimulant anorectics such as phentermine)

Risk & Side Effects

  • High: Gastrointestinal adverse events; lean-mass loss; gallbladder and biliary disease
  • Medium: Worsening of diabetic retinopathy; elevated resting heart rate; weight and cardiometabolic regain after stopping
  • Low: Acute pancreatitis, conflicted; non-arteritic anterior ischaemic optic neuropathy, conflicted; reduced bone mineral density; dehydration-related acute kidney injury, conflicted; suicidal ideation and self-harm, conflicted
  • Speculative: Thyroid C-cell tumours; pulmonary aspiration under anaesthesia

Monitoring

Marker Target Why
Fasting glucose 75–85 mg/dL Primary glycaemic target
Fasting insulin 2–5 µIU/mL Insulin resistance, earliest mover
HbA1c 4.8–5.4% 3-month average glucose
High-sensitivity C-reactive protein Below 0.8 mg/L Inflammation; largest low-dose effect
Apolipoprotein B Below 80 mg/dL Count of artery-damaging cholesterol particles
Triglycerides Below 80 mg/dL Hepatic fat handling
Alanine aminotransferase 10–26 U/L (men), 8–22 U/L (women) Liver fat and injury
Estimated glomerular filtration rate Above 90 mL/min/1.73 m² Kidney filtration; dehydration risk
Lipase Within laboratory reference range Pancreatic safety
Ferritin 50–150 ng/mL Iron status; absorption is reduced
Vitamin B12 500–900 pg/mL Deficiency risk from reduced intake
Thyroid-stimulating hormone 0.5–2.0 mIU/L Baseline thyroid status
Appendicular lean mass index No universal target; track change from own baseline, aiming for no loss Detects muscle loss early
Grip strength Above 35 kg (men), above 20 kg (women) Function, not just mass
Resting heart rate 50–65 beats per minute Dose-dependent adverse effect
Blood pressure Below 120/80 mmHg Cardiovascular benefit marker

Cadence: Symptom and weight check at 4 weeks, first repeat panel at 12 weeks, then every 6 months thereafter; body composition and grip strength every 6 months; lipid and inflammation panel annually once stable.

Qualitative Assessment

  • Reduction in food preoccupation, without loss of appetite at meals
  • Stable or improving training performance: load moved, repetitions completed, and session recovery
  • Energy through the afternoon, and absence of the post-meal slump
  • Absence of persistent nausea, early fullness or constipation; their appearance signals the dose is above the microdosing window
  • Sleep continuity and morning alertness