Compounded T4/T3: What it is and when people try it

If you still feel tired, cold, or foggy while taking levothyroxine (T4) alone, you might have heard about compounded T4/T3. This is a custom-made mix of T4 (levothyroxine) and T3 (liothyronine) made by a compounding pharmacy so the dose and ratio fit a person’s needs. Some people report better energy and mood; others notice no change. It’s not a miracle fix, but it can be the right choice for certain patients when used carefully.

Who might benefit and what to watch for

Doctors sometimes consider adding T3 if symptoms persist despite normal lab numbers on T4-only therapy, or when a patient has low free T3 levels. People who have had thyroidectomy or radioactive iodine may also try combination therapy. But T3 is a stronger hormone: too much can cause heart palpitations, anxiety, bone thinning, and trouble sleeping. If you have heart disease, osteoporosis, or are pregnant, talk to your provider before changing therapy.

Watch for red flags: fast heartbeat, chest pain, sudden weight loss, severe tremors, or new anxiety. If these happen, stop the new medicine and contact your clinician right away.

Practical tips: dosing, monitoring, and finding a safe pharmacy

Dosing varies a lot between people. A common approach is to keep most of the dose as T4 and add a small T3 amount—often 2.5–10 mcg of T3 per day split into two doses to reduce spikes. Some prescribers swap part of the T4 for T3 using a set ratio; others add a separate T3 pill. Your doctor should change doses slowly and check labs after 6–8 weeks, measuring TSH plus free T4 and free T3 when possible.

Get labs before starting and after each dose change. If your TSH goes too low or your free T3 is high, the dose may be too much. Also track symptoms—energy, sleep, heart rate, and mood—so you and your clinician can judge benefit versus side effects.

Pick a reputable compounding pharmacy. Ask if they follow USP standards, if they’re licensed in your state, and whether they test potency and provide a certificate of analysis. Avoid pharmacies that won’t share basic quality checks. Compounded meds are often not covered by insurance and can cost more than standard products.

Finally, work with a clinician who understands thyroid care and is willing to monitor you closely. Compounded T4/T3 can help some people, but it needs careful dosing, good labs, and a trustworthy pharmacy. If you’re curious, bring your recent labs and symptoms to a visit and ask whether a trial makes sense for you.