“Even though I don’t eat much, I keep gaining weight.”
“I feel tired every day, and even after getting plenty of sleep, I still have no energy.”
“I’m particularly sensitive to the cold, and my hands and feet are always cold.”
“I used to eat whatever I wanted without gaining weight, but now I gain weight after eating just a little.”
“Losing weight is becoming increasingly difficult. Could something be wrong with my metabolism?”
In today’s society, where people are paying more and more attention to body shape, health, and quality of life, these concerns are far from uncommon.
For many people, the first thoughts are:
Am I not exercising enough? Am I eating too much? Is it simply because I’m getting older?
But sometimes, the issue may not be just about diet and exercise. It may involve an often-overlooked organ—the thyroid gland.
In recent years, more and more people have discovered abnormal TSH levels or elevated thyroid antibodies during health checkups and have subsequently been diagnosed with Hashimoto’s thyroiditis or hypothyroidism.
In Japanese hospitals, one of the commonly used thyroid hormone replacement medications is: チラーヂンS錠 (Thyradin S)
Thyradin-S Levothyroxine Sodium Tablets 100 μg: 100 Tablets
1. Why Are More and More People Paying Attention to the Thyroid?
Modern lifestyles have changed significantly.
Long-term sleep deprivation, work-related stress, a fast-paced lifestyle, insufficient physical activity, and changes in dietary habits—combined with the increasing popularity of routine health checkups and screening—have made it easier to detect thyroid problems that may have previously gone unnoticed.
This is particularly relevant among women.
Hashimoto’s thyroiditis is relatively common among women.
Many people first discover the issue during a routine health checkup, when their results show:
Elevated TSH levels.
Further testing may then reveal:
Positive TPOAb and TgAb antibodies.
It is often only at this point that they realize:
“I’ve actually had a thyroid-related problem all along.”
2. How Important Is the Thyroid?
Although the thyroid is a relatively small gland, it plays an important role in regulating many essential physiological processes throughout the body.
Thyroid hormones are involved in:
Energy metabolism
Basal metabolic rate
Heart rate
Body temperature
Fat and carbohydrate metabolism
Nervous system function
Growth and development
Therefore, when thyroid hormone levels are insufficient, a range of changes may occur.
For example:
Fatigue, increased sensitivity to cold, dry skin, constipation, weight gain, and reduced mental energy or concentration.
However, these symptoms are not specific to hypothyroidism.
In other words:
Having these symptoms does not necessarily mean that you have hypothyroidism.
But if these symptoms persist for a long period of time, it may be worth discussing thyroid function testing with a healthcare professional.
3. Hashimoto’s Thyroiditis Does Not Necessarily Mean “You Need Medication Immediately”
This is a common misunderstanding.
Hashimoto’s thyroiditis is an autoimmune disease that affects the thyroid gland.
Some people may have:
Elevated TPOAb and TgAb levels
while still having:
Normal TSH and FT4 levels.
In such cases, not everyone needs to start thyroid hormone replacement therapy immediately.
Doctors generally consider multiple factors, including:
TSH
FT4
FT3
TPOAb
TgAb
Thyroid ultrasound findings
Clinical symptoms
Age
Whether the patient is planning pregnancy or is pregnant
Therefore:
“Having Hashimoto’s thyroiditis” does not automatically mean “you need to take Thyradin S.”
What really matters is:
whether thyroid function has been affected and whether treatment is medically indicated.
4. What Exactly Is チラーヂンS
チラーヂンS錠 (Thyradin is a commonly used thy
Its active in
レボチロキシンナトリウム水和物
comm
Levothyroxin
Simply put:
When the thyroid gland canno
Therefore, the core purpose of Thyradin S is not to “stimulate the thyroid” or “burn fat.”
Rather, it is:
To replace thyroid hormon
5. The Question Many People Care About Most: Can Thyrad
The answer is very clear:
It should not be used as a weight-loss medication.
This is an important dist
If a person has hypothyroidism, appropriate treatment may h
But this is completely different from saying:
“Taking thyroid hormone can
For people with normal thyroid function, taking thyroid hormone or increasing the dosage on their own for weight loss is not an appropri.
Excessive thyroid hormone
Palpitations
Rapid heartbeat
Tremors
Excessive sweating
Anxiety
Insomnia
Chest discomfort
There
Thyroid hormone therapy is treatment—not a weight-loss method.
6. Why Do Some Peop
Th
Some people start taking Thyradin S and then wonder:
“My
The reason is simple:
Normal thyr
Body weight i
Diet
Total calorie intake and the balance of carbohydrates, f
Physical Activity
Daily activity
Sleep
Long-term sleep deprivation may affect appetite, stress levels, and lifestyle habits.
Age
As people age, muscle m
Insulin Resistance and Other Meta
For some people, weight-related issues are not caused by thyroid function alone.
Th
7. Why Does Thyradin S Require Regular Follow-Up Testing?
Thyroid h
“Take it today and know the final
Doctors usually arrange follow-up blood tests depending on the
Commonly monitored indicators include:
TSH
and:
FT4
When necessary,
FT3
may also be assessed.
Based on the results, the doctor determines whet
This is why:
Thyradin S should not be
In particular, it is dangerous to assume:
“My weight hasn't gone down, so maybe I need a higher dose.”
8. In the Curren
In recent years, weight
From low-carbohydrate diets and intermittent fasting to GLP-1 medications, weight loss has become a major he
But the more attention we pay to weight management, the more important it is to a
For some people
For others, it may be insufficient physical activity.
For some, it may be poor sleep.
Some
Others may have abnormal thyroid function.
And in
Therefore, if you have persistent:
Weight gain + fatigue + cold sensitivit
rather than continually trying different weight-loss methods, it may be worthwhile to undergo a proper medical evaluation.
In particular, thyroid function tests such as:
TSH and FT4
may be worth discussing with a healthcare professional.
9. For People Taking Thyradin S, What Matters Most Is Not “How Much,” but “Whether the Dose Is Appropriate”
Thyradin S is available in different strengths.
The appropriate dose needs to be determined by a doctor based on the individual patient’s condition.
Some people may require a lower dose.
Others may require a higher dose.
The dosage may also be adjusted during treatment based on follow-up test results.
Therefore, seeing someone else taking 50 μg, 75 μg, or 100 μg does not mean that the same dosage is appropriate for you.
Thyroid hormone replacement therapy requires individualized dosing.
10. If You Suspect a Thyroid Problem, Here Are Some Signs to Pay Attention To
If you experience the following symptoms persistently, consider discussing with a healthcare professional whether thyroid function testing is appropriate:
① Significant fatigue
You used to feel energetic, but now you frequently feel tired or weak.
② Increased sensitivity to cold
Other people feel comfortable, but you often feel unusually cold.
③ Persistent weight gain
Your diet has not changed significantly, yet your weight continues to increase.
④ Dry skin
Persistent and noticeable dry skin, particularly when accompanied by other symptoms.
⑤ Constipation
A noticeable change in your usual bowel habits.
⑥ Changes in heart rate or mental state
Especially when several symptoms occur together, further evaluation may be worthwhile.
Of course, these symptoms can also be caused by other medical conditions or lifestyle factors.
Therefore, symptoms alone cannot establish a diagnosis.
11. What Really Matters Is Thyroid Function, Not Simply the Antibody Numbers
Many people become worried when they see the following on their health check report:
TPOAb ↑
TgAb ↑
They may immediately think:
“My thyroid function must already be very poor.”
But elevated thyroid antibodies do not necessarily mean:
“Thyroid function is already significantly impaired.”
Doctors need to consider TSH, FT4, symptoms, and other relevant tests together.
Therefore, if your thyroid antibodies are elevated, don't panic and don't start thyroid hormone medication on your own.
First, have a proper evaluation of your thyroid function and discuss the next steps with a healthcare professional.
Modern society is paying increasing attention to health, and that is a positive development.
But one of the biggest mistakes in health management is:
Seeing one symptom and diagnosing yourself, or seeing a medication and assuming it is a weight-loss drug.
Thyradin S is a prescription medication used for thyroid hormone replacement therapy.
Its true purpose is:
To help replace thyroid hormone when the body is unable to produce enough of it.
It is not a dietary supplement and not a weight-loss medication.
If you suspect that you may have Hashimoto’s thyroiditis or hypothyroidism, a proper thyroid function evaluation can be a reasonable place to start.
Understand your body first, then determine whether treatment is necessary.
After all, effective health management is not about:
“Which medication works fastest?”
It is about:
Finding the real problem and receiving the right treatment.