What do you think of my T4-T3 ratio?


Feb 9, 2013
I'm trying to figure out how I should change my thyroid dosage and could use some help.

Background if you haven't read my other threads: I only have 1/2 a thyroid (cancer) so have been taking meds for 5 yrs now. I believe I am hypo (cold hands and feet all the time among other symptoms) and was so even before I got thyroid cancer. In the past couple years I mega dosed iodine which caused me have to lower my dosage, but I've stopped that now so I'll definitely need to increase/change my dosage.

I read this quote from Peat about how he suggests supplementing:

An effective way to use supplements is to take a combination T4-T3 dose, e.g., 40 mcg of T4 and 10 mcg of T3 once a day, and to use a few mcg of T3 at other times in the day. Keeping a 14-day chart of pulse rate and temperature allows you to see whether the dose is producing the desired response. If the figures aren't increasing at all after a few days, the dose can be increased, until a gradual daily increment can be seen, moving toward the goal at the rate of about 1/14 per day

Currently I take the natural dessicated thyroid from Erfa plus some Synthroid.
Erfa has 18 mcg T4 and 4 mcg T3.
My Synthroid is 50 mcg.

So all up I am getting 68 mcg of T4 and 4 mcg of T3 daily.

So that's WAY off the 4:1 ratio that it sounds like Peat is suggesting. It's 17:1!

Problem is, whenever I've tried to lower the T4 by cutting the Synthroid dose in half I've not felt as good and had terrible breakouts. But according to my bloodwork, my ranges are fine with either 50 or 25 mcg of Synthroid... not that that proves anything.

What I'm thinking of doing is doubling my Erfa (so that would mean 36 mcg T4 and 8 mcg T3) and reducing my Synthroid in half (25 mcg) for a total of 61 mcg T4 and 8 mcg T3. This would be an 8:1 ratio though, so not sure if that is too dramatic of a change from 17:1.

If anyone has any thoughts on what may be happening with me and ideas on what I should do now, I would be very grateful. Why do I seem to need so much T4 and have an adverse reaction when I lower it? What would be the best way to change my meds to fix this hypo situation?


Thread starter
Feb 9, 2013
Just realized I made a mistake in the above, I am getting 85 mcg of T4 and 8 mcg of T3 daily... so an 11:1 ratio.

I actually wrote to Dr. Peat and this was his reply:

The liver has to convert T4 to T3 for it to be effective. It needs glucose and selenium to make the conversion. Adequate protein, at least 80 grams per day, is necessary. Sea food, once a week will provide selenium, two quarts of milk and a quart of orange juice would provide many of the other essential nutrients. Taking T4 at bedtime sometimes is helpful. Most people feel best on a ratio of T4:T3 of 4:1 or less. Checking the relaxation rate of the Achilles reflex is a quick way to check the effect of the thyroid on your nerves and muscles; the relaxation should be instantaneous, loose and floppy.

So I guess he's not going to give me any specifics on where to start with my dosage other than to try and get it to a 4:1 ratio (if not 3:1).

Based on what I am currently taking that could mean keeping my dose the same in the a.m. and just adding 25 mcg of T3 (Cytomel) split up every few hours throughout the day. That would get me to a 3.1 to 1 ratio. However I'm not sure if it's a good idea to start with so much, maybe I better build up to all that T3 gradually.

Also I suppose adding more T3 may gradually reduce my need to have the T4 so high?!... argh this is so confusing :(


Thread starter
Feb 9, 2013
@jnhermann, why do you recommend ditching the Erfa? I read a quote from Peat saying he personally uses Cynoplus (a T3/T4 combo) and Cytomel (T3 only). Are you saying this because the ratio is better with the Cynoplus (a perfect 4:1 instead of 4.4 to 1 with the Erfa)? Or some other reason?

Whenever I have lowered my T4 from 85 mcg to 60 mcg (by halving my Synthroid) I don't feel as good and I break out.
If I got rid of the Erfa then I'd only be taking 50 mcg of T4 so I imagine I'd feel even worse.
Unless I increased the Synthroid dosage up to 75 mcg to make up for it.

I guess I don't understand what's so bad about Erfa?


Feb 13, 2013
Nothing against erfa, just that its natural and results can be a mixed bag. So you are now taking some synthetic t4, plus some natural t4 and natural t3. Probably would be easier to stick with synthroid for t4 and add cytomel or cynomel for t3. If you want to watch a very good video series on how to take and increase thyroid go to www.hopeforhashimotos.com. its free. He shows you exactly what to do, including if you are already on synthroid/t4. You need to monitor pulse and body temperature. Labs wont tell you when you are optimal but pulse and body temps will. You want to start very small with t3. Maybe 5 micrograms for 7+ days, then bump up again. Watch the videos. He explains it very well.

Have you tested your thyroid antibodies? Apparently about 9 out of 10 people that are hypo have antibodies. If you do, the antibodies will act on the dessicated thyroid, possibly hindering its effectiveness. Thus, synthetic would probably be a better choice in this case.
Similar threads
Thread starter Title Forum Replies Date
Advocate2021 Feedback on Thyroid Supplementation T4:T3 ratio 4:1 vs 3:1 Supplements, Pharmaceutical Drugs 0
md_a ACE/ACE2 Ratio: A Key Also in 2019 Coronavirus Disease (Covid-19)? Scientific Studies 1
shine PQQ inhibits lactate formation, increases lactate to pyruvate conversion, improves NAD+/NADH ratio Scientific Studies 0
G Calcium-Phosphorus Ratio In Animal Protein Sources: What To Choose? Diet 7
J Walnuts Improve N-6/n-3 Ratio Fats 10
haidut Alcohol Causes Liver (and Other Organ) Damage By Lowering NAD/NADH Ratio Scientific Studies 0
fever257 Ideal Macronutrient Ratio - 22y/o Male, 175 Lbs Macros & Micros 2
Ben Stone Calcium In Excess Of Seawater Ratio Dangerous Ray Peat Topics 25
C Higher Carb To Protein Ratio Results In Higher Testosterone And Lower Cortisol In Men (1987) Scientific Studies 5
V Foods With A Good Glycine / Methionine Ratio Diet 1
Hans The Peat Ratio Of Foods (Glycine Vs Methionine, Cysteine And Tryptophan) Discussing Dietary Models 29
round How Do You Balance Glucose To Fructose Ratio? Using Rice Water ? Weight 1
C Great Article On NAD+:NADH Ratio And The Randle Cycle Metabolism 6
N Vitamin D And K Ratio D 1
Amazoniac What Ratio Of Vitamin E To K2 Works Best For You? Vitamins 3
Velve921 Ca:p Ratio - 3:1 Almost Completely Abolishes Anxiety Diet, Recipes 32
Twohandsondeck Anecdotes - Calcium:phosphate Ratio Improvements Anyone? Minerals 21
R PUFA Conversion Ratio Confusion Polyunsaturated Fats, Seed Oils 2
F Calcium-Magnesium Ratio Diet 29
J Is This Estrogen/Progesterone Ratio E-dominant? Blood Work, Labs 0
E I Want Facial Gains Using K2 MK4 What Ratio With Other Supps? Vitamins 12
PurpleHeart We Are Probably Wrong About Calcium/magnesium Ratio Minerals 14
PurpleHeart Testosterone/Epitestosterone Ratio And Baldness Hair & Nails 34
A Calcium To Phosphorus Ratio In Chocolate/Eating Chocolate After A Meal Sweets, Snacks 2
A What's A Good Ratio Of Calcium : D3 : K2? Health 1
A Fat Solubles: What's A Good Ratio, And Why? A / D / E / K2 Vitamins 8
x-ray peat EMF From Electric Shavers Have A 11:1 Odds Ratio Of Causing Cancer Scientific Studies 73
M Copper / Zinc Ratio Ask For Help or Advice 48
G Progesterone/estrogen Ratio Progesterone 0
S LH/FSH Ratio Importance? Male Issues 1
ecstatichamster What's The Significance Of BUN/urea Ratio Blood Work, Labs 3
JohnBonham SO. CONFUSED. Sodium/Potassium Ratio, Mineral Balance Sodium 16
D Phophorous And Nervousness/mental Agitation: Wisdom On Ca:phos Ratio From Past Bodybuilding Sphere Diet 6
Momado965 Ratio Of Safa To Pufa Polyunsaturated Fats, Seed Oils 0
DaveFoster 1:1 Ratio For T3:T4 T3 & T4 21
AretnaP Be Really Careful With Copper/zinc Ratio If Your Diet Isn't Super PUFA-free Toxins, Detoxification 8
Ulysses Caffeine To Sugar Ratio Blood Sugar 12
haidut Inosine Increases NAD/NADH Ratio And Reduces Systemic Inflammation Scientific Studies 30
cyclops Good Ratio Of Glycine To Proline With Muscle Meat? Supplements, Pharmaceutical Drugs 4
R Good Ratio Of Aspirin To Baking Soda, Niacinamide, Glycine, Vit K? Aspirin 5
haidut NAD/NADH Ratio - The One Metabolic Cause To Rule Them All Science 190
RedStaR Facial Width-to-Height (fWHR) Ratio Scientific Studies 77
E IGF1 : IGFBP3 Ratio As A Predictor Of Male Vertex Balding Scientific Studies 26
haidut High Cortisol / Testosterone Ratio As A Likely Cause Of PTSD Scientific Studies 16
beachbum Mascarpone Cal To Phos Ratio Is Very Good Cheese 0
W No Thyroid - T3 T4 Ratio And Diet Supplements, Pharmaceutical Drugs 2
P Does Weight Lifting Have Effect On Anabolic Androgenic Ratio? Exercise 7
P Excess Linoleic Acid Increases Collagen I/III Ratio And “Stiffens” The Heart Muscle Following High F Articles & Scientific Studies 1
DrJ Calcium-Phosphorous Ratio Of Cheeses Minerals 46

Similar threads