91-120mg up to 2 grain
91-120mg up to 2 grain is a prescriber-directed compounded preparation prepared or dispensed for patient-specific use within the Hormone Optimization therapy area. Genesis should dispense this medication only pursuant to a valid prescription and the prescriber's clinical judgment.
This preparation represents a compounded thyroid hormone formulation in the range of 91–120 mg (up to 2 grains), providing T4 and T3 in the established grain ratio of approximately 38 mcg T4 and 9 mcg T3 per 60 mg grain. At 2 grains (120 mg), patients receive approximately 76 mcg T4 and 18 mcg T3 — the upper end of the standard maintenance range for adult hypothyroidism. Genesis Compounding prepares this as a patient-specific, prescriber-directed 503A preparation; it is not FDA-approved as a compounded preparation.
| Active Ingredient | Pharmacologic Role |
|---|---|
| Levothyroxine (T4) ~57–76 mcg (proportional to ordered strength) | Prohormone thyroid hormone converted peripherally to active T3, activating nuclear TRα/TRβ receptors to regulate basal metabolic rate, thermogenesis, cardiac chronotropy, and protein synthesis. |
| Liothyronine (T3) ~13.5–18 mcg (proportional to ordered strength) | Active thyroid hormone with direct, high-affinity nuclear thyroid hormone receptor binding, producing potent and rapid thyromimetic effects at approximately four-fold greater potency per microgram than T4. |
Oral administration (capsule or tablet), on an empty stomach 30–60 minutes before the first meal.
- Swallow whole with water.
- Separate from absorption-inhibiting agents (calcium, iron, antacids, cholestyramine, sucralfate) by at least 4 hours.
The 91–120 mg range is the upper standard maintenance range for most adults with primary hypothyroidism:
- At 120 mg (2 grains), patients receive approximately the maximum dose at which most patients' thyroid hormone requirements are met before malabsorption or compliance issues are implicated.
- Doses above 180 mg generally suggest malabsorption or non-compliance rather than a true requirement.
- TSH, free T4, and free T3 should be measured 4–6 weeks after reaching this range and at least annually when stable.
- All dosing is prescriber-determined.
- Levothyroxine (T4): Converted to T3 by peripheral deiodinase enzymes; T3 activates TRα and TRβ nuclear receptors, driving transcriptional regulation of metabolic, cardiovascular, and growth-related genes.
- Liothyronine (T3): Direct nuclear receptor agonist producing immediate thyromimetic effects on heart rate, metabolic rate, and thermogenesis with approximately four-fold greater per-microgram potency than T4.
The 91–120 mg dose range represents the upper standard maintenance tier for adult hypothyroidism. Clinical use includes:
- Patients with complete thyroid gland absence (post-thyroidectomy, radioiodine ablation) who require full exogenous thyroid hormone replacement.
- Larger adults or those with increased thyroid hormone clearance who need doses at the upper end of the maintenance range.
- In patients near 120 mg who fail to achieve TSH normalization, consider evaluation for malabsorption (celiac disease, atrophic gastritis), non-compliance, or drug interactions before dose escalation.
Monitoring: TSH (target individualized, typically 0.5–2.5 mIU/L), free T4, and free T3 at 4–6 weeks post-adjustment; annually when stable. Cardiac and bone assessments as clinically indicated.
Contraindications:
- Untreated adrenal insufficiency; active thyrotoxicosis; acute MI; hypersensitivity to components.
Warnings & Precautions:
- At this dose range, monitoring for thyrotoxic side effects is particularly important: palpitations, arrhythmia, angina.
- Long-term supratherapeutic TSH suppression is associated with atrial fibrillation and osteoporotic fractures.
- Biotin assay interference — hold supplements ≥48 hours before thyroid function labs.
Drug Interactions:
- Warfarin: enhanced anticoagulant effect; INR monitoring required.
- Calcium, iron, antacids, sucralfate: significantly impair absorption; separate ≥4 hours.
- CYP enzyme inducers (phenytoin, rifampin): may increase thyroid hormone metabolism, requiring dose increases.
Common Side Effects: Palpitations, tachycardia, tremor, excessive sweating, heat intolerance, weight loss, insomnia, diarrhea at supratherapeutic doses.
Store at room temperature (15–25°C), protected from light, heat, and moisture. Keep tightly sealed. Do not refrigerate. Keep out of reach of children. Observe the beyond-use date labeled by Genesis Compounding per USP <795>.
Is this a high dose of thyroid hormone?
91–120 mg is the upper end of the standard maintenance range for most adults. It is not considered a suppressive dose (used in thyroid cancer management) but is at the range where careful monitoring for thyroid excess is particularly important.
What if my TSH doesn't normalize at 120 mg?
Failure to respond to doses approaching 2 grains (120 mg) may suggest malabsorption (e.g., celiac disease, atrophic gastritis), drug interactions affecting absorption or metabolism, or non-compliance. Your prescriber will investigate these possibilities before further dose escalation.
How often are lab tests needed?
At 4–6 weeks after reaching this dose, then at least annually when stable on a consistent dose. Recheck sooner if symptoms change or new medications are started.
Is this preparation FDA-approved?
No. This is a patient-specific, 503A compounded preparation from Genesis Compounding and is not FDA-approved as a finished drug product.
What are signs of too much thyroid hormone at this dose?
Palpitations, rapid or irregular heartbeat, tremor, excessive sweating, heat intolerance, unintended weight loss, and insomnia. Contact your prescriber promptly if these occur.
Clinical References
Authoritative sources reviewed in preparing this clinical summary. Provided for prescriber reference; not a substitute for the prescriber’s clinical judgment.