Increase Your Synthroid Dose Immediately
Your TSH of 6.207 mIU/L while taking Synthroid 100mcg indicates inadequate thyroid hormone replacement and requires a dose increase. 1, 2
Why Your Current Dose Is Insufficient
Your TSH is elevated above the target range of 0.5-4.5 mIU/L, confirming that 100mcg is not providing adequate thyroid hormone replacement. 1, 2 The median TSH level at which levothyroxine therapy is typically initiated has decreased from 8.7 to 7.9 mIU/L in recent years, and your level of 6.207 mIU/L clearly warrants treatment optimization. 1
Recommended Dose Adjustment
Increase your Synthroid by 12.5-25 mcg to a new dose of either 112.5 mcg or 125 mcg daily. 1 The specific increment depends on your age and cardiac status:
- If you are under 70 years old without cardiac disease: Increase by 25 mcg to 125 mcg daily. 1, 3
- If you are over 70 years old or have cardiac disease: Increase by 12.5 mcg to 112.5 mcg daily to avoid cardiac complications. 1, 3
Larger dose adjustments should be avoided as they may lead to overtreatment and iatrogenic hyperthyroidism. 1
Monitoring Protocol After Dose Adjustment
Recheck your TSH and free T4 in exactly 6-8 weeks after the dose increase. 1, 2, 3 This interval is critical because levothyroxine requires 4-6 weeks to reach steady state in your system. 3 Testing earlier will give falsely abnormal results and lead to inappropriate dose adjustments. 1
Continue adjusting the dose by 12.5-25 mcg increments every 6-8 weeks until your TSH reaches the target range of 0.5-4.5 mIU/L. 1, 2, 3
Once your TSH stabilizes in the normal range, monitor annually or sooner if symptoms change. 1, 2
Risks of Leaving Your TSH Elevated
Persistent TSH elevation at this level carries approximately 5% annual risk of progression to overt hypothyroidism. 1 Undertreatment causes:
- Persistent hypothyroid symptoms (fatigue, weight gain, cold intolerance, constipation) 1
- Adverse cardiovascular effects including delayed cardiac relaxation and abnormal cardiac output 1
- Unfavorable lipid profiles with elevated LDL cholesterol 1
- Reduced quality of life 1
Critical Pitfalls to Avoid
Do not adjust your dose too frequently. Wait the full 6-8 weeks between adjustments to avoid overshooting and causing iatrogenic hyperthyroidism. 1, 3
Take your Synthroid correctly: On an empty stomach, 30-60 minutes before breakfast, with a full glass of water. 3 Take it at least 4 hours apart from iron, calcium supplements, or antacids, as these interfere with absorption. 3
Do not assume your hypothyroidism is permanent without reassessment. If this is new-onset hypothyroidism, confirm it's not transient thyroiditis by ensuring TSH remains elevated on repeat testing. 1 However, given you're already on 100mcg, this likely represents established hypothyroidism requiring lifelong treatment.
Watch for overtreatment after dose increase. If you develop symptoms of hyperthyroidism (palpitations, tremor, heat intolerance, weight loss), contact your physician immediately. 1 Approximately 14-21% of treated patients develop iatrogenic subclinical hyperthyroidism, which increases risk for atrial fibrillation, osteoporosis, and fractures. 1, 2