Phase 4: T3 Thyroid Therapy (Rebooting Your Metabolism)

Get medical supervision before T3 if any of these apply

T3 raises your heart rate and metabolic demand. At the doses described here it is real medicine with real risk. Do not start T3 on your own if any of the following apply. Work with a doctor who can monitor you.

A heart rhythm problem or heart diseaseArrhythmia, atrial fibrillation, or known heart disease. T3 can push an unstable heart into dangerous territory.

Known osteoporosis or low bone densityLong-term, high-dose T3 can accelerate bone loss.

On anticoagulants such as warfarinT3 can change how these drugs behave, so dosing may need medical adjustment.

Pregnant, or a history of thyrotoxicosisThese call for specialist oversight before any thyroid hormone.

Resting heart rate already above 90 bpmResolve that first. An elevated resting heart rate is a contraindication to starting T3.

Many people with chronic illness are stuck in a state where their body is “hibernating” to save energy. Even if your blood tests look normal, your body might not be using thyroid hormones correctly. This phase uses a hormone called T3 to “reboot” your body’s thermostat and turn your energy back on.

Is This Therapy Right for You?

Main Requirements (You must have these)

1. Low Waking Temperature:Is your temperature consistently below 36.5°C (97.7°F) first thing in the morning? This is the main sign your metabolism is slow.

2. Low Heart Rate:Is your resting heart rate below 72 beats per minute? This also suggests a slow metabolism.
Note: If your resting heart rate is above 90 bpm, resolve that first — elevated resting HR is a contraindication for starting T3 therapy.

Other Common Symptoms

(Check how many you have – the more you have, the more likely you need this)

Always tired or waking up exhausted
Brain fog, trouble concentrating, or memory loss
Cold hands and feet even when it’s warm
Gaining weight easily or unable to lose it
Dry skin or hair that is thinning/falling out
Feeling low, anxious, or irritable
Muscle and joint aches
Frequent headaches or swelling (fluid retention)

Quick Check:

Low Morning Temp + Low Pulse + 3 or more symptoms → You may be a good candidate for T3 therapy.

Track your temp and pulse for one week to be sure.

Getting an Accurate Temperature Reading

Use a Basal Body Thermometer, Not a Standard One

Your waking temperature is one of the most important data points in this entire protocol. A cheap drugstore thermometer that reads to one decimal place is not good enough. You need a thermometer precise enough to detect meaningful shifts, the kind used for tracking fertility windows.

Digital basal body temperature thermometer for precise tracking

A digital basal body thermometer that reads to two decimal places and holds the result for easy reading

What to Use:A digital basal body thermometer, the kind sold for fertility tracking (ovulation monitoring). These read to two decimal places (e.g., 36.48°C rather than 36.5°C), which gives you the precision needed to track real trends over days and weeks. They are inexpensive and widely available online or at pharmacies.

How to Take It Correctly:Place the thermometer under the tongue and hold it there for at least 60 seconds before the reading locks. Most standard thermometers beep too early. A basal thermometer is designed to wait for a true stable reading. Take it before getting out of bed, before drinking anything, and at roughly the same time each morning. Movement, eating, and even sitting up will raise your temperature and give you a false reading.

What You Are Looking For:Log your temperature every morning. You are tracking a trend, not a single number. As T3 therapy works, you should see your waking temperature gradually climb toward 36.5–37.0°C (97.7–98.6°F) and stabilize there. Erratic readings, persistent sub-36°C temperatures, or a temperature that rises but then drops again are all meaningful signals worth noting.

Introduction to T3 Therapy

Overview: This therapy uses T3 (thyroid hormone) to help with fatigue and low body temperature. The goal is to “restart” your metabolism. You can dive deeper into it on this site: wilsonssyndrome.com

Wilson’s T3 Therapy & Dry Fasting for Chronic Illness: a detailed breakdown of why this combination works when nothing else has.

The Best Way: Slow-Release T3 (SR-T3)

We strongly recommend using Slow-Release T3 (SR-T3).

Why? It keeps your hormone levels stable all day and night. It doesn’t cause sudden spikes like regular T3.
Evening Use: You can take it in the evening to help your metabolism while you sleep.
Easier to Use: You don’t have to keep taking small doses throughout the day.

Where to Get T3

One trusted source for Slow-Release T3 is chronic-illness.st. They specialize in this medication and can ship to many places. (Previously chronic-illness.ca — the site has recently migrated.)

If you have trouble getting your medication, Yannick can help you find a way to get what you need.

Why Your Blood Tests Might Lie to You

The Real Problem: Tissue-Level Resistance

Most doctors look at your blood to see if you have enough T3. But just because T3 is in your blood doesn’t mean it’s getting inside your cells where it’s needed. This is called tissue-level resistance.

Side-by-side: the same lab result, two completely different cellular realities. This is why “your labs are normal” is not the answer chronic illness patients need.

Think of T3 as a “key” and your cells as “doors.” In many sick people, the locks are jammed. The T3 keys are floating around in the hallway (your blood), but they can’t get into the rooms (your cells) to turn on the power. When a doctor draws your blood, they see plenty of keys and say, “You’re fine!” Even though your body is actually starving for energy.

Brain Insulin Resistance

This problem is especially serious in the brain. When T3 can’t get into your brain cells correctly, it leads to a type of “brain insulin resistance.” This causes major brain fog, memory problems, and severe fatigue. Even if you eat enough food, your brain can’t use that energy properly without the T3 “key” to unlock the process.

Other Signs of Resistance:

Low Body Temperature: If your cells don’t have enough T3, they can’t create heat. This is why you feel cold even if your blood tests are “normal.”
High Reverse T3: Sometimes your body makes a “fake key” called Reverse T3 that blocks the real T3 from working.
Adrenal Stress: When your cells are starving for energy, your body pumps out stress hormones (like cortisol) to try to keep you going. This eventually leads to total burnout.

T3 therapy is used to “electrify” the body, sending a structured “electrical signal flood” of abundance and shock to finally force those jammed locks open and wake your body up. This convinces the cells that T3 can enter again and radically increases insulin sensitivity. Depending on the case, this may require a mix of T4 and high T3, or just T3, but the concept of a short, powerful energy burst remains the same. Do not forget to understand the critical co-factors required for T3 therapy to be safe and effective.

The Role of Genetics: In some cases, your genetics can play a big role in how your body handles T3. Fasting, stress, and low-carb can have different effects on different people. To learn more about this, visit the Genetic Polymorphisms page.

When to Start T3: The Fasting Block Integration

Start T3 on Day 3 of the Water Fast, Not After

In the Scorch Protocol, T3 therapy does not begin at the refeed. It begins on day 3 of the water fast that follows the 5-day dry fast. This timing is intentional.

By starting T3 on day 3 of the water fast, you are on T3 day 3 when you have your first calories. This matters because T3 needs to already be running when refeeding begins It supports your metabolism, keeps your kidneys in a stronger state, and crucially, it means your antiviral protocol (L-lysine + monolaurin) can start immediately on refeeding day 1. You do not need to wait for kidney rehydration before beginning antivirals.

Adjust for Body Composition:The day-3 window assumes you are carrying enough body fat. If you are very lean or close to skin-and-bones, starting T3 that early can trigger an adrenaline surge, so wait further into the refeed before you begin. If you have more body fat to work with, day 3 of the water fast is the ideal start. When you are unsure, this is a timing call worth confirming with Yannick directly.

The Ramp During the Fast:Follow the standard 15 mcg/day climb. Water fast day 3 = 15 mcg (T3 day 1). Water fast day 4 = 30 mcg (T3 day 2). Water fast day 5 = 45 mcg (T3 day 3). You then continue climbing into the refeed from there, with T3 day 4 being your first day of eating.

Also a High-Risk Window for Viral Reactivation:When T3 cycles end and doses taper down, your metabolic rate temporarily dips. This creates the same energetic trough that triggers herpesvirus reactivation during the fast-to-refeed transition. Continue antiviral coverage during T3 wind-down until your waking temperature has stabilized at your baseline for 5–7 consecutive days.

The 30-Day T3 Cycle

This plan is designed to wake up your body’s metabolism. It involves a 10-day “climb” followed by a 20-day “descend.”

Phase	Time	What to Do
The Climb	10 Days	The Hike Up: Increase your total daily dose by about 15 mcg every single day. Example: Day 1 = 15mcg, Day 2 = 30mcg, Day 3 = 45mcg... Note: Split your total dose into two parts: one in the morning and one in the evening.
The Peak	1–3 Days	Stay at your highest dose for a few days to “break” your metabolism’s resistance. If your heart races or you feel anxious, stop increasing.
The Taper	20 Days	The Hike Down: Slowly lower your dose back to zero. This lets your thyroid start making its own hormones again without a crash.

Figure 1: Simplified T3 Protocol Dosing & Tracking Chart

Safety First

Is your heart racing?If your resting heart rate is over 100 beats per minute, → STOP INCREASING. Stay at your current dose or lower it until your heart rate slows down.

Are you using “Instant” T3?→ WARNING: This fast 10-day climb is only for Slow-Release T3. Do not try this with regular “instant” T3 unless you are very careful and take many small doses throughout the day.

Having trouble stopping?→ If you feel bad while lowering your dose, your doctor might suggest a small dose of T4 to help your body adjust.

Drug Interactions to Review Before Starting

Thyroid can thin blood, especially at higher doses. Patients on warfarin sodium (Coumadin®) or other anticoagulants may develop an increase in prothrombin time requiring a lowering of their anticoagulant therapy while taking thyroid medication. Drug-drug interactions may occur with other anticoagulants, oral hypoglycemic agents (increased requirements), insulin (increased requirements), estrogens and oral contraceptives (increased thyroid requirement), tricyclic antidepressants (enhanced effects), cardiac glycosides (potential toxicity and reduced dose) and cholestyramine (decreased T3 and T4 absorption). Several drugs, including cimetidine, ranitidine, glucocorticoids, amiodarone and beta-receptor antagonists, have been reported to increase the hepatic metabolism of T4 into reverse T3 by inhibiting 5’-desiodinase, the hepatic microsomal enzyme catalyzing the conversion of T4 into T3.

Keeping Your Progress

Supplements: Take B-Complex vitamins, Vitamin C, and electrolytes to help your body.
Diet: Eat plenty of protein to keep your metabolism strong.
Bone Health: Take Vitamin K2 to keep your bones healthy during this therapy.
Success: When you are finished, your waking temperature should stay between 36.5°C and 37.0°C (97.7°F - 98.6°F) without any medicine.

The Co-Factor Stack That Makes T3 Stick

T3 reboots metabolism, but whether it holds depends on three things going right at the same time: you have to eat enough, you have to sleep, and your stress hormones have to come down instead of spiking. The protocol uses a small co-factor stack to protect all three.

Cyproheptadine (appetite, sleep, stress, mitochondria):This is a first-cycle tool with one primary job: drive you to eat dramatically more food so you fill the wider metabolic eating window T3 opens. Without sufficient calories T3 burns muscle, not fat. Cyproheptadine fixes that by restoring the appetite T3 demands. It also calms a hypersensitive, nauseated gut by quieting the brain-gut nerves (the same mechanism behind its well-established use for cyclic vomiting and abdominal migraine in children), which makes eating much larger amounts tolerable even when the gut is not ready.

Additional effects: cortisol, sleep, and mitochondrial uncouplingIt blunts the serotonin and cortisol surge that T3 can provoke, reducing muscle catabolism and settling the nervous system into the calm state mitochondria need to respond to T3 instead of fighting it. As an anti-serotonin drug it also supports mitochondrial uncoupling: the mitochondria burn fuel to produce heat, which raises body temperature and metabolic rate, directly supporting what T3 is driving. And it is T3-sparing: some patients who barely respond to T3 are tempted to push the dose above the roughly 150 mcg/day Wilson’s protocol ceiling, which carries more cardiac and adrenal risk. Adding cyproheptadine often lets the existing T3 dose reach the target temperature instead, avoiding that escalation. Dose is 1 to 4 mg in the evening, set individually in your consult. See the Symptom Management page for MCAS context and the ketotifen comparison.

First-cycle only: stop before hGH. Cyproheptadine blunts growth hormone directly, so it is stopped before the second T3 cycle where hGH does the rebuilding. There is a second reason to stop it: hGH fat-burning at night depends on nocturnal cortisol, and cyproheptadine blunts that nocturnal cortisol. Running cyproheptadine during the hGH phase works against the hGH phase on both fronts. Do not run them together.

Low-dose aspirin (inflammation, cortisol, insulin sensitivity):Lowers the inflammatory drag and peripheral cortisol conversion that keep cells resistant to T3. See the Tips & Tricks aspirin section for dosing and safety.

Vitamin K2 (vascular protection):Non-negotiable alongside aspirin to protect clotting and arterial health, and it supports the bone health T3 therapy demands. Use MK-4 or MK-7.

None of these replace T3. They are what keep T3 working long enough to reset your baseline.

Ideal body temperature curve throughout the day for a healthy person

Figure 2: The ideal body temperature curve of a healthy person, rising through the day and peaking in the late afternoon. If your T3 therapy works, your temperature pattern should begin to match this curve.

Thermoregulation across five cycles of slow-release T3 therapy in a 51-year-old woman, showing waking temperature climbing from a sub-36°C baseline toward the healthy 36.5–37.0°C range

Figure 3: Real-world thermoregulation data across five cycles of slow-release T3 in a 51-year-old woman. Each cycle progressively lifts the waking temperature baseline toward the healthy 36.5–37.0°C range shown in Figure 2 — the pattern most participants follow when the protocol is working.

Fueling T3 Therapy: Why Calories Matter Here

T3 dramatically increases your metabolic rate. That is the point. But a faster metabolism with insufficient fuel will cannibalize muscle. You must not be in a caloric deficit during this phase.

Match Your Caloric Demand:As T3 doses climb, your body burns more energy. If you are not eating enough to cover that demand, the body will turn to muscle tissue for fuel, the opposite of what you are trying to achieve. Keep calories at or above your target (see the Refeeding page) and prioritize protein to give your body something to build with, not just burn.

Move Your Muscles: Tell Your Brain to Keep ThemPhysical movement during T3 therapy sends a preservation signal. Your body will not aggressively break down muscle tissue it is actively using. You do not need to train hard. Even walking, light resistance work, or bodyweight movements daily is enough to keep the muscle-sparing signal active. Lying still while on T3 with insufficient calories is the worst combination.

When You Cannot Hit High Calories Yet:Some people, especially early in the refeed, cannot physically eat enough to match T3’s demand. Their gut is not ready, appetite is suppressed, or digestion is too compromised. In this case, there are specific strategies that can help:

hGH: directly shifts the body toward anabolism and preferential fat use, reducing the rate at which muscle is burned for fuel even when calories are temporarily low.
Retatrutide: a GLP-1/GIP/glucagon triple agonist that improves glucose utilization and raises baseline energy availability. The glucagon component is particularly useful for people stuck in low-energy states.
Cyproheptadine: the primary first-cycle lever for filling the eating window when appetite is broken or the gut is hypersensitive. It restores the drive to eat, calms the brain-gut nerves that make large meals nauseating, and deepens sleep when repair on T3 happens. For many people this is the single cheapest way to get calories back up early in the refeed. See the stop-before-hGH caveat: cyproheptadine is a first-cycle tool and is stopped before hGH.

Important: If you do not understand how hGH or Retatrutide work and why they are recommended in this context, do not use them. These are not general supplements. They are targeted tools with specific mechanisms. Read the hGH Therapy page and understand the protocol before considering them.

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References

Cahill GF Jr. Starvation in Man. New England Journal of Medicine, 1970. — the fasting-metabolism timeline: the brain's shift to ketones and muscle sparing once ketosis is established, and why T3 must be paired with adequate fuel
Influence of absolute (dry) fasting on metabolic processes and organ function. — profound insulin suppression and improved insulin sensitivity (HOMA-IR) during fasting

See the full research & citations page for the complete evidence base and how each study is used.