15mg / 1/4 grain
15mg / 1/4 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 is a compounded thyroid hormone preparation at 15 mg (one-quarter grain), providing approximately 9.5 mcg levothyroxine (T4) and 2.25 mcg liothyronine (T3) per dose. This is a very low initiation strength used when beginning thyroid hormone therapy, particularly in patients with cardiovascular concerns, long-standing myxedema, or in elderly individuals requiring careful titration. 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) ~9.5 mcg per 15 mg (¼ grain) | Prohormone thyroid hormone that undergoes peripheral deiodination to active T3, regulating metabolism, cardiac output, and thermoregulation via nuclear thyroid hormone receptor activation. |
| Liothyronine (T3) ~2.25 mcg per 15 mg (¼ grain) | Active thyroid hormone with direct, high-affinity binding to nuclear TRα and TRβ receptors, producing rapid thyromimetic effects at even low microgram amounts. |
Oral administration (capsule or tablet).
- Administer on an empty stomach, 30–60 minutes before breakfast.
- Swallow with water; do not crush.
- Maintain ≥4-hour separation from absorption-inhibiting agents (calcium, iron, antacids, bile acid sequestrants).
The 15 mg (¼ grain) strength is the lowest standard initiation dose, recommended by established clinical guidance for:
- Patients with long-standing myxedema, suspected cardiovascular compromise, or advanced age.
- Starting dose is 15 mg/day; the prescriber will increase by 15 mg increments every 2–3 weeks based on TSH, free T4, free T3, and clinical response.
- Angina or worsening cardiac symptoms should prompt immediate dose reduction and prescriber reassessment.
- All dosing decisions are made by the prescribing clinician.
- Levothyroxine (T4): Converted peripherally to T3 by type 1 and type 2 deiodinases; T3 then binds TRα/TRβ nuclear receptors and modulates transcription of metabolic, cardiovascular, and developmental target genes.
- Liothyronine (T3): Directly and rapidly occupies nuclear thyroid hormone receptors with high affinity, producing genomic and non-genomic thyromimetic effects on cardiac rate, metabolic rate, and thermogenesis.
The 15 mg (¼ grain) strength is specifically indicated for cautious initiation of thyroid hormone replacement in high-risk populations:
- Elderly patients with possible occult coronary artery disease.
- Patients with severe or longstanding hypothyroidism (myxedema).
- Post-cardiac event patients requiring thyroid replacement under careful monitoring.
Monitoring:
- TSH and free thyroid hormones at baseline and 4–6 weeks after dose initiation.
- Cardiac assessment before initiation when cardiovascular risk is elevated.
- Titrate dose very gradually with this population — appearance of angina mandates dose reduction.
Contraindications:
- Untreated adrenal insufficiency.
- Active thyrotoxicosis.
- Recent acute myocardial infarction.
- Hypersensitivity to components.
Warnings & Precautions:
- Particularly important at initiation: even small doses may unmask or exacerbate angina in susceptible patients.
- Diabetes: monitor glucose, as thyroid replacement may alter insulin sensitivity.
- Hold biotin ≥48 hours before thyroid function tests.
Drug Interactions:
- Warfarin: thyroid hormones enhance anticoagulant effect; monitor INR carefully during initiation.
- Calcium, iron, sucralfate, bile acid sequestrants: impair absorption significantly.
Common Side Effects: At therapeutic doses, side effects are minimal. Supratherapeutic effects include palpitations, tachycardia, sweating, insomnia.
Store at controlled room temperature (15–25°C), in a dry location away from light and humidity. Keep out of reach of children. Observe the beyond-use date labeled by Genesis Compounding. Discard after BUD.
Why is my dose only ¼ grain?
A 15 mg (¼ grain) starting dose is recommended for patients who may be at higher cardiovascular risk or who have had prolonged hypothyroidism. Starting low and titrating slowly minimizes the risk of precipitating cardiac events during initiation.
How often will my dose be increased?
Typically, the prescriber increases the dose by 15 mg every 2–3 weeks, guided by your symptoms and thyroid laboratory results. The pace of titration depends on your individual clinical situation.
When is the best time to take this?
Take on an empty stomach 30–60 minutes before breakfast, with water. Avoid calcium, iron, and antacids within 4 hours of your dose.
Is this preparation the same as a commercial thyroid product?
No. This is a patient-specific compounded preparation from Genesis Compounding and is not FDA-approved. It is formulated to provide T4 and T3 in a clinically established ratio under prescriber direction.
What should I do if I experience chest pain or palpitations?
Contact your prescriber or seek emergency care immediately. These symptoms may indicate the dose is too high or that an underlying cardiac condition has been unmasked.
Clinical References
Authoritative sources reviewed in preparing this clinical summary. Provided for prescriber reference; not a substitute for the prescriber’s clinical judgment.