When we talk about the most comomly aromatase inhibitors(AI) for bodybuilders, there must comes out the name of Letrozole. What is Letrozole, how it works and how should bodybuilders use it ? Let’s talk about it.
What is Aromatase inhibitors Letrozole?
Letrozole belongs to a class of drugs called nonsteroidal aromatase inhibitors(AI). It is administered orally and is a selective aromatase inhibitor. It prevents the production of estrogen by aromatase by competitively and reversibly binding to the heme of its nocicin P450 unit, thereby reducing the amount of estrogen in the body and preventing estrogen effects.
Letrozole is used to treat breast cancer that can also help prevent breast cancer recurrence and is also used to treat early breast cancer in women who have been treated with the drug moxifen (Nolvadex) for five years.
As bodybuilder, we mainly want to understand the role of Letrozole for bodybuilder. Letrozole is a reversible aromatase inhibitor that is considered to be the most potent nonsteroidal AI. It is one of the three aromatase inhibitors most commonly used by anabolic steroid users to control estrogen-related side effects associated with the use of aromabolic steroids. The other two common types of AI are non-steroidal Arimidex and steroidal Aromasin.
Letrozole reduces bodybuilder’s overall estrogen levels, primarily helping bodybuilder combat gynecomastia and water retention caused during anabolic steroids, and also helps prevent high blood pressure that may occur if excess water retention is not address.
Classification of aromatase inhibitors (AI)
AI is aromatase inhibitor. Aromatase, also known as estrogen synthetase, is a key enzyme in estrogen biosynthesis.
Aromatase inhibitors are either steroidal or non-steroidal, first, second or third generation. Steroid AI such as Esimetane inhibits the activity of aromatic crisp by mimics the substrate androstenedione, and non-steroid AI such as Anastrozole and letrozole inhibit the activity of aromatase by binding to the enzyme’s red blood iron. First-generation AI, such as aminoglutamine, is relatively weak and nonspecific, and they also block other steroidogenic enzymes that require adrenal steroid supplementation. The third generation AI is effective, does not inhibit related enzymes and is well tolerated.
Letrozole and anastrozole inhibited female aromatase by nearly 100% and reduced plasma estradiol levels in men by about 77%.
How does Aromatase inhibitors Letrozole work?
Letrozole is use to treat breast cancer in women because in women, the ovaries produce estrogen. After menopause, the ovaries stop producing estrogen, but the body makes estrogen through an enzyme called aromatase. Cancer cells need estrogen to grow. The aromatase inhibitor Letrozole inhibits aromatase activity and reduces the amount of aromatase in the body, thereby preventing the body from producing more estrogen. In this way, cancer cells are starved of estrogen, which acts as food, preventing their growth.
The main hormones in women are estrogen, but there are also androgens. Similarly, the main hormone in men is estrogen, but there are also androgens. In both men and women, the levels of androgens and oestrogen are in balance and maintain their respective functions.
When male bodybuilders use anabolic steroids to aid bodybuilding, the supplementation of exogenous AAS disrupts the balance between androgens and estrogens in the body, resulting in corresponding side effects.
The influence of exogenous AAS supplementation on male bodybuilder is manifeste in two aspects. One is that a large amount of exogenous AAS supplementation will lead to the inhibition of endogenous testosterone level, resulting in low testosterone level. The other is that a large amount of exogenous AAS is converted by aromatase into a large amount of estrogen, with male breast development, water retention and other estrogen side effects. At the same time, the production of large amounts of estrogen further inhibits the hypothalamic-pituitary-testicular axis, making it difficult for testosterone levels to return to normal.
Letrozole experiment
Letrozole is a powerful aromatase inhibitors (AI) that is very effective in controlling estrogen. Using Letrozole, which inhibits aromatase activity and prevents large amounts of androgens from being converted into large amounts of estrogen, can reduce the overall estrogen level of bodybuilder, thus avoiding the occurrence of uncontrolled estrogen side effects. At the same time, when Letrozole inhibits aromatase activity in the body, the body’s normal estrogen levels are also inhibited, which leads to the suppression of the hypothalamic-pituitary-testis negative feedback mechanism, and estrogen fails to turn off the hypothalamic-pituitary-testis axis, resulting in a continuous increase in the body’s production of gonadotropin, which in turn produces more natural testosterone.
People conducte An experiment to determine the level of free testosterone. 225pmol/l severely obese men (BMI > 35kg/m2) and 2.5mg of Letrozole weekly treatment increased free testosterone from 163+/-13pmol/l to 604+/-50pmol/l after 6 weeks. Total testosterone levels in all subjects rose to within the normal range, while free testosterone levels rose to superphysiological levels in seven of the 12 men. Total free testosterone levels were stable in 12 men between six weeks and six months of treatment.
In addition using it to treat gynecomastia cause by excessive estrogen, also using Letrozole to delay epiphylaxis maturation in boys and increase adult height in boys with non-gonadotropin-dependent precocious puberty, idiopathic short stature, and systemic delayed puberty. Meanwhile, Letrozole was well tolerate.
Aromatase inhibitors Letrozole dosage
Letrozole controls the effects of estrogen, which helps eliminate the side effects of estrogen and also helps restore the body’s endogenous testosterone levels. Therefore, Letrozole is useful for either bodybuilding cycle or pct cycle.
Letrozole dosage for bodybuilding cycle
Bodybuilders use Letrozole during the bodybuilding cycle as an anti-estrogen agent. However, side effects of incorrect or excessive Letrozole use can affect normal bodybuilding. Fatigue, a side effect of excessive use of Letrozole, will affect the effect of bodybuilding. So it’s important to understand the Letrozole dosage for bodybuilding cycle.
The medical dose of Letrozole is 2.5mg per day, and when using Letrozole in the bodybuilding cycle, it is not normally higher than this dose. The bodybuilder Letrozole dosage is generally 0.5mg to 1.25mg to balance the Letrozole’s dosage against the estrogen’s dosage.
Increase the bodybuilder Letrozole dosage to 2.5mg per day only if the bodybuilder already shows signs of gynecomastia. Once Gyno symptoms disappear, the Letrozole dosage should be reduced.
Letrozole dosage for pct cycle
Letrozole facilitates the release of gonadotropin which helps restore the body’s endogenous testosterone levels and thus is suitable for the pct cycle. This is similar to the effect of clomiphene (Clomid).
However, the pct cycle does not reduce estrogen indefinitely, but rather brings estrogen and androgen levels in the body to a state of equilibrium before AAS supplementation. If estrogen production is completely blocked in men, being too low can actually have the opposite effect. Because Letrozole reduces men’s estrogen levels indefinitely, bodybuilder abandonedLetrozole for PCTS by using the selective estrogen regulator Clomid. A lower dose of Letrozole for pct should also be considered if a bodybuilder constitution is more effective with Letrozole to avoid completely blocking estrogen production in the body.
However, in the pct cycle, bodybuilder also uses another selective estrogen regulator, tamoxifen (Nolvadex). When male bodybuilders use Letrozole and Nolvadex together, the two drugs have been shown to reduce the effectiveness of each other. Therefore, most people choose to use Nolvadex and Clomid for pct cycle and Letrozole for bodybuilding cycle.
Letrozole vs Clomid
Both Letrozole and Clomid are used to treat hormone-responsive breast cancer.
Letrozole is an aromatase inhibitor that is only effective in postmenopausal women. Because at this point, estrogen is produced by aromatase and is mainly found in peripheral tissues (i.e. fat tissue, such as the breast) and in many parts of the brain. In premenopausal women, where the main source of estrogen is the ovary rather than aromatase, Letrozole is not effective.
For male bodybuilders, a large amount of estrogen in the body is basically due to aromatase conversion of aromatolytic AAS. So Letrozole is very effective at blocking male estrogen.
Instead of acting through aromatase, Clomd is a selective estrogen receptor modulator that binds to the estrogen receptor and prevents the estrogen in the body from binding to it. So Clomid use was not associated with menopause. It’s more useful for women.
So, do all male bodybuilders choose aromatase inhibitors Letrozole?
No. Letrozole completely blocks estrogen, suitable for male bodoybuilder to quickly reduce estrogen levels, but not suitable for male bodybuilder body estrogen and androgen level balance. Therefore, Letrozole is used by male bodybuilder to rapidly lower estrogen and treat gynecomastia (gyno), but Clomid is still preferred for pct cycle.
In addition to fighting gynecomastia, Letrozole also prevents water retention. This gives Letrozole an unexpected ability to modify the bodybuilder’s shape, resulting in a harder, drier, and torn appearance. Letrozole is therefore particularly useful for bodybuilders who wish to eliminate fluid retention as much as possible and is suitable for use in the bodybuilding cycle.
Aromatase inhibitors Letrozole side effects
Different people experience different side effects with different drugs, and it is also necessary to choose the right drug for them according to their own drug reactions. For Letrozole, users have reported several side effects.
Hot flashes and sweating
Low estrogen levels can cause hot flashes and sweating, a side effect that, while causing some discomfort, is not dangerous.
This side effect reduce by trying to reduce spicy foods, caffeine, smoking and alcohol consumption. Keep the room clean and use a fan appropriately.
Dysphoria
Avoid caffeine in the afternoon and evening. Keep your sleeping environment dark and quiet, and try to go to bed and wake up at the same time each day. Stop watching TV and using electronic devices like phones or tablets at least an hour before bedtime.
Feel very tired
Letrozole can cause fatigue and make you feel tired. Possibly because Letrozole lowers estrogen levels so much, men still need some low levels to function properly. Low doses of Letrozole help mitigate this reaction.
To avoid this side effect, bodybuilder usually chooses to take Letrozole at night.
Gentle exercise and a healthy diet can help you reduce fatigue. Try to go to bed and wake up at the same time every day. If you feel very tired while taking Letrozole, do not drive, ride a bicycle, or operate machinery. If the problem doesn’t gradually improve as your body gets used to the medication, consult your doctor.
I feel sick and lose my appetite
Taking Letrozole after meals may help. If you feel sick or lose your appetite, you can choose to eat your favorite foods and try to eat smaller meals more often.
Mild muscle or bone pain
Muscle or bone pain is a symptom associate with aromatase inhibitors, not just Letrozole, but other aromatase inhibitors as well. This is because in addition to androgens, estrogen also helps maintain healthy bones. Long-term use of Letrozole reduces estrogen levels in the body, which can lead to bone loss. This bone loss can lead to joint pain. Estrogen may also play a role in how nerves perceive pain.
Letrozole is usually use in combination with calcium and vitamin D supplements to strengthen bones.
Non-steroidal anti-inflammatory drugs also use to relieve pain. If the pain lasts longer than a week, consult your doctor.
Alopecia
Some women who have used Letrozole for breast cancer have experienced thinning hair because Letrozole dramatically reduces the women’s estrogen levels. For male Bodybuilders using Letrozole, the effect of Letrozole on hair is essentially negligible. Androgen is responsible for 99.9 percent of hair loss that affects men.