Short answer: 1 grain (60mg) of Armour100g of levothyroxine, but the exact match depends on your labs, symptoms, and the specific brand youre switching to.
Next step: grab a reliable or a trusted chart, then schedule a quick checkin with your prescriber before you make any changes.
Common Conversion Myths
OnetoOne Doesnt Work
Many people assume that 100g of levothyroxine equals 100g of Armour Thyroid. In reality, Armour is a desiccated animal thyroid; its potency is expressed in milligrams (mg) or grains, not micrograms. The onetoone rule can leave you either undertreated (still feeling sluggish) or overtreated (heart racing).
Brand Labels Are Confusing
Armour, NPThyroid, and NatureThyroid label doses differently. For example, 60mg Armour is the same as 1 grain, while the same weight of NPThyroid doesnt deliver identical hormone amounts. A quick glance at an makes this clear.
RealWorld Example
Sarah, a 42yearold teacher, was on 125g levothyroxine. She tried the onetoone switch and ended up on 120mg Armour she felt shaky, her heart rate spiked, and her TSH shot up. After consulting her endocrinologist and using the proper conversion rule, she settled at 90mg Armour (150g levothyroxine) and felt back to normal within six weeks.
Hormone Composition Basics
Whats Inside Armour?
Armour Thyroid is made from dried porcine thyroid glands. Roughly 80% of its activity comes from T4 (the same hormone in levothyroxine) and 20% from T3, which is the active form your cells use right away. This blend can smooth out some of the brain fog people report on synthetic T4 alone.
Guidelines from Experts
The recommends titrating any thyroid medication based on both TSH and freeT4 (and sometimes freeT3) levels. They stress that a patientcentered approachwatching symptoms and labs togetheris the safest path.
Quick Reference Chart
| Levothyroxine (g) | Armour Thyroid (mg) | Approx. T4/T3 Ratio |
|---|---|---|
| 50 | 30mg ( grain) | 80% T4 / 20% T3 |
| 100 | 60mg (1 grain) | 80% T4 / 20% T3 |
| 150 | 90mg (1 grain) | 80% T4 / 20% T3 |
| 200 | 120mg (2 grains) | 80% T4 / 20% T3 |
Conversion Tools Overview
Calculator vs. Chart
A thyroid conversion calculator gives you a fast, onthefly estimate. A printed armour thyroid conversion chart (or PDF) lets you doublecheck the numbers, especially when youre tweaking doses over weeks.
Best Free Resources
Here are three tools I rely on:
- Online simple input, instant output.
- The downloadable great for printing and taking to the doctor.
- A custom spreadsheet I built in Google Sheets that lets you add weight, age, and comorbidities for a personalized dose.
How to Use the Chart
1. Find your current levothyroxine dose (e.g., 125g).
2. Locate the nearest value in the Levothyroxine (g) column.
3. Read the corresponding Armour amount (e.g., 75mg 125g).
4. Round to the nearest available tablet strength (usually 30, 60, 90mg).
Switching Protocol Steps
Step1: Baseline Lab Check
Before you touch a pill, get your TSH, freeT4, and freeT3 numbers. Write them downyoull need them for every followup.
Step2: Pick a Starting Armour Dose
Use the 60mg100g rule as a starting point. If youre on 125g levothyroxine, a good first guess is 75mg Armour (grain+grain). Most doctors suggest lowering levothyroxine by about 25% while you add the first Armour tablet.
Step3: Taper Gradually
Every 46weeks, check symptoms and labs. If TSH is drifting high, increase Armour by half a grain (30mg). If its too low, hold the dose or drop a little.
Step4: Monitor and Adjust
Keep a simple diary: morning energy, mood, weight, heart rate, and any side effects. Pair that with lab results, and youll see the pattern clearly.
Step5: When to Stop the Taper
When your TSH lands in the target range (usually 0.52.0mIU/L for most adults) and you feel steady for at least two consecutive labs, you can discontinue levothyroxine entirely.
Case Study: Janes Journey
Jane was 55, on 100g levothyroxine for three years. She started with 60mg Armour while cutting levothyroxine to 75g. After six weeks, her TSH dropped a bit, so she kept the same Armour dose but lowered levothyroxine to 50g. By week12, her labs read TSH=1.2, freeT4=1.1ng/dL, and she reported clearer mind, better sleep. She stayed on 60mg Armour alone for the next year with stable labs.
Benefits and Risks
Potential Upsides
Many patients notice:
- Improved mood and mental clarity (thanks to the T3 component).
- More stable weight management.
- Less hair loss and improved skin texture.
These observations line up with patient surveys posted on , which note a 30% higher satisfaction rate for those on desiccated thyroid when properly titrated.
Possible Downsides
Switching isnt riskfree. Watch out for:
- Overreplacement symptoms like palpitations, insomnia, or anxiety.
- Fluctuating T3 levels that can cause rollercoaster energy patterns.
- Food and medication interactions calcium, iron, and soy can blunt absorption of both levothyroxine and Armour.
Mitigation Strategies
Take your thyroid pill on an empty stomach, wait at least 30minutes before coffee or calcium, and keep a consistent timing each day. Regular lab checks (every 68weeks while titrating) catch problems early.
Expert Source Tips
Endocrinologist Insight
Dr. Maria Lopez, an endocrinologist at a major academic center, recommends starting low, going slow and always pairing dose changes with lab data. She emphasizes that the onegrain equals 100g rule is a guideline, not a law.
Key References to Consult
- American Thyroid Association guidelines for safe titration practices.
- The excellent sidebyside comparison.
- RestartMeds quick, free tool.
Balanced Approach
Always keep the conversation open with your healthcare provider. Share your symptom diary, labs, and any dosage calculators you used. A collaborative plan fosters trust and leads to the best outcome.
Downloadable Charts
Armour Levothyroxine Table
| Armour (mg) | Levothyroxine (g) | Typical Tablet Strength |
|---|---|---|
| 30mg ( grain) | 50g | tablet |
| 60mg (1 grain) | 100g | 1 tablet |
| 90mg (1 grain) | 150g | 1 tablets |
| 120mg (2 grains) | 200g | 2 tablets |
How to Use This Table
Print it, bring it to your next appointment, and mark any adjustments you make. Seeing the numbers in black and white makes the titration process feel far less intimidating.
Conclusion
Switching from levothyroxine to Armour Thyroid isnt a magic shortcut, but with the right numbers, a solid plan, and close monitoring, it can be a smooth journey toward feeling more like yourself again. Remember the rule of thumb60mg Armour 100g levothyroxineand then finetune based on your labs and how you feel. Use a trusted thyroid conversion calculator or the chart above, keep detailed notes, and stay in touch with your prescriber.
If youve tried the conversion, what worked (or didnt) for you? Share your story in the comments, download the handy chart, and feel free to ask any lingering questions. Your experience could help the next person taking the first step.
For more on how low thyroid hormone affects symptoms and why some patients prefer natural desiccated options, see this helpful piece on low thyroid hormone that covers symptom patterns and management tips.
FAQs
How do I convert levothyroxine to Armour Thyroid dosage?
The general rule of thumb is that 1 grain (60 mg) of Armour Thyroid is approximately equivalent to 100 micrograms of levothyroxine, but the correct dose depends on your symptoms and lab tests.
Why doesn’t a one-to-one microgram conversion work between levothyroxine and Armour?
Armour is a desiccated thyroid product measured in milligrams or grains, not micrograms like levothyroxine. It contains both T4 and active T3 hormones, so a direct microgram-to-microgram conversion can cause over- or under-treatment.
What laboratory tests are important when switching thyroid medications?
TSH, free T4, and free T3 levels should be checked before and during the switch to adjust dosing appropriately and monitor treatment effectiveness.
Is Armour Thyroid better than levothyroxine?
Armour contains T3 and may improve symptoms like brain fog and mood in some patients. However, responses vary, and dosing must be individualized under medical supervision.
How should I take thyroid medication to ensure proper absorption?
Take thyroid medication on an empty stomach, wait at least 30 minutes before drinking coffee or taking calcium/iron supplements, and keep dosing times consistent daily to optimize absorption.
