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CAS 566-48-3 Fat Burning Steroids Formestane Lentaron Pharmaceutical Intermediates

Good quality Androgenic Anabolic Steroids for sales
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CAS 566-48-3 Fat Burning Steroids Formestane Lentaron Pharmaceutical Intermediates

China CAS 566-48-3 Fat Burning Steroids Formestane Lentaron Pharmaceutical Intermediates supplier
CAS 566-48-3 Fat Burning Steroids Formestane Lentaron Pharmaceutical Intermediates supplier CAS 566-48-3 Fat Burning Steroids Formestane Lentaron Pharmaceutical Intermediates supplier

Large Image :  CAS 566-48-3 Fat Burning Steroids Formestane Lentaron Pharmaceutical Intermediates

Product Details:

Place of Origin: China
Brand Name: No brand
Certification: ISO9001,USP,GMP
Model Number: 566-48-3

Payment & Shipping Terms:

Minimum Order Quantity: Negotiation
Price: Negotiation
Packaging Details: Disguised package or as required
Delivery Time: Within 3 working days after payment
Payment Terms: T/T, , MoneyGram,Bitcoin
Supply Ability: 500kg per week and mass stock
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Detailed Product Description
CAS: 566-48-3 Assay: 99% Min
MF: C19H26O3 MW: 302.41
Appearance: White Powder Grade: Pharmaceutical Grade
Usage 1: Loss Weight Usage 2: Treat Breast Cancer
High Light:

Fat Cutter Steroids


Weight Loss Steroids

CAS 566-48-3 Fat Burning Steroids Formestane Lentaron Pharmaceutical Intermediates


Formestane is currently one of the best legal anti-estrogens out there.It is classified as an irreversible arromatase inhibitor, meaning, it destroys the aromatase enzyme.Formestane is a synthetic steroidal substance with antineoplastic activity.Formestane binds irreversibly to and inhibits the enzyme aromatase, thereby blocking the conversion of cholesterol to pregnenolone and the peripheral aromatization of androgenic precursors into estrogens.


1. Quick Details:


Product name: Formestane,Lentaron,4-hydroxyandrostenedione
Other name: Lentaron;FORMESTAQNE;hydroxyandrostenedione
Chemical Name(s): 4-Hydroxyandrost-4-ene-3, 17-dione;4-hydroxy-4-androstene-3,17-dione;4-Hydroxyandrostenedione
CAS: 566-48-3
Molecular Formula: C19H26O3
Molecular Weight: 302.41
Appearance: White crystalline powder
Assay: 99%
Delivery: EMS,DHL,FedEx ,TNT,ect
Grade : Pharmaceutical Grade
Application : Used for natural or artificial postmenopausal breast cancer patients, including tamoxifen and other endocrine treatment of patients is invalid. Used for breast cancer.


2. Description:


Lentaron, a.k.a. formestane, belongs to a class of drugs known as 2 (or second generation) aromatase inhibitors which are primarily used in the treatment of estrogen-receptor positive breast and ovarian cancers in post-menopausal women. Some cancers require estrogen to grow, and aromatase is an enzyme that synthesizes estrogen. Aromatase Inhibitors (AIs) are a class of drugs that effectively block this synthesis thereby lowering estrogenic levels, and slowing the growth of cancers.

AIs are categorized into two types: 1) non-steroidal inhibitors such as Arimidex (anastrozole) and Femara (letrozole) which inhibit the enzyme by reversible competition and; 2) irreversible steroidal inhibitors such as Aromasin (exemestrane) which form a permanent bond with the aromatase enzyme complex. Lentaron is classified in the second group as a selective irreversible steroidal aromatase inhibitor. Derived from androstenedione (the same except for the addition of a 4-hydroxyl group), formestane forms an irreversible bond with the aromatase enzyme which permanently deactivates it. It takes several days (following formestane discontinuation) for aromatase to become active again. These types of drugs are often referred to as suicidal aromatase inhibitors because the drugs seemingly sacrifice themselves (their structural independence) in the process of blocking estrogen.

3. Fuction of Formestane/ Lentaron:


Formestane (Lentaron,4-hydroxyandrostenedione ) is a steroidal aromatase inhibitor used in the treatment of estrogen-receptor positive breast cancer in post-menopausal women.


Formestane is often used to suppress estrogen production from anabolic steroids or prohormones. It also acts as a prohormone to 4-hydroxytestosterone, an active steroid which displays weak androgenic activity in addition to acting as a mild aromatase inhibitor.


Formestane has poor oral bioavailability and as such is no longer popular as many orally active aromatase inhibitors have been identified.


4-hydroxyandrostenedione significantly reduces plasma levels of estrogen and has shown antitumour activity in postmenopausal women with breast cancer.


In comparative studies, the clinical efficacy of intramuscular (injected) formestane 250mg did not differ significantly from that of oral megestrol when administered as second-line endocrine therapy to patients with advanced disease in whom previous tamoxifen therapy had failed.


Formestane produced a response rate, duration of response and overall survival rate that was not significantly different from that of oral tamoxifen when administered as first-line endocrine therapy to patients with advanced disease, but tamoxifen was superior in some measures.

4. Characteristics:


Formestane is a steroidal aromatase inhibitor, known as a suicidal inhibitor because it permanently binds to the aromatase enzyme.


Formestane was originally used as an injectable for breast cancer patients, but due to its possible androgenic effects it has largely been replaced by non-steroidial AIs in the medical community. Most of its use is now is limited to the bodybuilding community since it is available as a legal dietary supplement for reducing estrogen and increasing testosterone production.


Although formestane can effectively reduce estrogen through oral consumption, its low oral bioavailability has lead to the development of several transdermal based products (which appear to offer higher efficacy at a lower dose).


Relative to 6-oxo and ATD, Formestane is a more potent aromatase inhibitor, which appears to effectively reduce natural estrogen levels by as much as 50% within several days (while higher doses may further suppress estrogen). Because of formestanes potent ability at reducing estrogen it will tend to reduce HDL levels, while increasing LDL levels, thus harming the cholesterol profile. For this reason, it is recommended to limit cycles of formestane to 8 weeks max.


Because formestane also has a strong affinity for the 5a-reductase enzyme it will reduce DHT levels in the body by effectively competing with testosterone for the 5a-reductase.


Formestane converts to the active androgen 4-hydroxytestosterone which has about half the anabolic potency, and about 25% of the androgenic potency as testosterone. This would suggest that fairly high doses of formestane (800-1000mg/day) could lead to some level of anabolic enhancement (although the amount required for this would surely lead to undesirably low estrogen levels).

Formestane is successfully used as a standalone during re-composition cycles to help reduce “bloat” and fat storage. It can also be used as an anti-estrogen to counter aromatization of aromatizing steroids.




Average Dose:


Aromatase inhibition
100-200mg/day (transdermal)
150-250mg/day (oral)

Anabolic effects
800-1000mg/day (oral)

Average Cycle Length:

4-8 weeks




6. COA:


Description White Crystalline Powder white powder
Identification Positive Positive
Assay 97.0~103.0% 99.31%
Melting Point 172~178℃ 172.0~176.0℃
Specific Rotation +34~ +38¡ã(C=2,in dioxane) +36.3¡ã
Loss On Drying 1.0%max in vacuum over P2O5 for 4h 0.26%
Residual Solvents meets the requirements. Conforms
Organic Volatile Impurities meets the requirements. Conforms
Conclusion The specification conform with USP30 standard


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CAS 566-48-3 Fat Burning Steroids Formestane Lentaron Pharmaceutical IntermediatesCAS 566-48-3 Fat Burning Steroids Formestane Lentaron Pharmaceutical Intermediates



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