akn
Musclechemistry Member
Description:
Testolactone is a first generation non-selective steroidal
aromatase inhibitor, used clinically to treat estrogendependent
breast cancer. Its exact mode of action is
unknown, but it is believed to inhibit the aromatase
enzyme in a noncompetitive and irreversible manner. If so,
this would be an activity that is very similar to that of
Lentaron (formestane). This might also explain why
cessation of the drug does not provide an immediate
restoration of normal estrogen production. Like
formestane, it takes several days after ceasing use for the
body to recover its normal estrogen synthesizing capacity,
which is the time required by the body to replenish its
enzyme levels. It seems logical based on structure and
action that the same thing occurs with testolactone.
Although testolactone is technically steroidal in structure,
it offers no anabolic or androgenic effect to its user. This is
because it does not possess the traits necessary to bind
and activate the androgen receptor, namely an active 17beta-
hydroxyl group. In fact, its D ring is an unusual sixmembered
lactone ring, and not the normal fivemembered
carboxylic ring that testosterone and its
derivatives normally possess. This is likely where
testolactone got its name, which may be short for
testosterone-lactone. Studies actually suggest this
steroidal drug possesses some level of anti-androgenic
action, which likely occurs via competitive inhibition of the
cellular androgen receptor. Regardless of this,
testolactone has been included in the u.S. controlled
substance list as an anabolic/androgenic steroid. For the
purposes of this reference book it will remain classified as
an anti-estrogenic drug. Likewise, testolactone is used by
athletes and bodybuilders not to increase muscle mass
and performance, but to mitigate the estrogenic side
effects caused by certain anabolic/androgenic steroids.
Note that the level of aromatase inhibition produced with
testolactone is significantly lower than that produced by
the newer selective third generation inhibitors such as
anastrozole, letrozole, and exemestane. For example, one
study conducted in 1985 showed that 1,000 mg of
testolactone per day given to nine normal men for a period
of ten days suppressed serum estradiol levels by 250/0 .
Another using the same 1,000 mg dose noted a 500/0
reduction after six days of use. These numbers are lower
than what would be expected of the newer thirdgeneration
agents given the substantial estrogen
suppression figures they have produced during clinical
trials with women.
History:
Testolactone was first approved as a prescription drug by
the FDA back in 1970.lt was an early anti-estrogenic drug,
exhibiting a moderately pronounced effect but failing to
reach levels of high clinical success. As other more effective
medications began to surface for the treatment of breast
cancer, testolactone would not see the success its
developers likely planned for it. It would see production in
a small number of countries outside the U.S., most notably
Brazil, Germany, and Chile. It has since been discontinued in
all countries but the U.S., where the Teslac brand is still
available.
How Supplied:
Testolactone is most commonly supplied in tablets of 50
mg.
Structural Characteristics:
Testolactone is classified as a steroidal noncompetitive
irreversible steroidal aromatase inhibitor. It has the
chemical designation 13-hydroxy-3-oxo-13,17secoandrosta-
1 ,4-dien-17-oic acid [dgr ]-Iactone.
Side Effects:
Common side effects associated with the use of an
aromatase inhibitor include hot flashes, joint pain,
weakness, fatigue, mood changes, depression, high blood
pressure, swelling of the arms/legs, and headache. In 1999,
the FDA officially added malaise to the list of possible side
effects from this drug, reflecting something bodybuilders
had noticed for some time: low estrogen levels can lead to
lethargy, as this sex hormone plays an important role in the
functioning of the central nervous system. Aromatase
inhibitors may also decrease bone mineral density,.which
may lead to osteoporosis and an increase in fractures in
susceptible patients. Some individuals may also respond to
the medication with gastrointestinal side effects including
nausea and vomiting. Aromatase inhibitors can harm the
development of an unborn fetus, and should never be
taken or handled during pregnancy. When taken by men
(as an off-label use) to reduce estrogenicity during
prolonged periods of steroid treatment, aromatase
inhibitors may increase cardiovascular disease (CVD) risk
by retarding some beneficial properties of estrogen on
cholesterol values. Studies have demonstrated that when
an aromatizable steroid such as testosterone enanthate is
taken in conjunction with testolactone, suppression of
HDL (good) cholesterol levels becomes significantly more
pronounced. Since the estrogen receptor
agonist/antagonist Nolvadex® generally does not display
the same anti-estrogenic (negative) effect on cholesterol
values, it is usually favored over aromatase inhibitors for
estrogen maintenance by male bodybuilders and athletes
concerned with cardiovascular health.
Administration:
Testolactone is FDA approved as adjunctive therapy in the
palliative treatment of advanced or disseminated breast
cancer in postmenopausal women when hormonal
therapy is indicated. It may also be used in women who
were diagnosed as having had disseminated breast
carcinoma when premenopausal, in whom ovarian
function has been subsequently terminated. The
recommended dosage is 250 mg taken 4 times per day.
When used (off-label) for estrogen suppression in male
steroi,d users, a dosage of 250 mg (five tablets) is usually
ta ken per day.
Availability:
Testolactone is no longer commonly used in clinical
medicine, and consequently is not manufactured on a
large sale globally. Presently a small number of
testolactone preparations still exist, but are not commonly
diverted for sale on the black market given the very low
demand for the drug in this population.
Testolactone is a first generation non-selective steroidal
aromatase inhibitor, used clinically to treat estrogendependent
breast cancer. Its exact mode of action is
unknown, but it is believed to inhibit the aromatase
enzyme in a noncompetitive and irreversible manner. If so,
this would be an activity that is very similar to that of
Lentaron (formestane). This might also explain why
cessation of the drug does not provide an immediate
restoration of normal estrogen production. Like
formestane, it takes several days after ceasing use for the
body to recover its normal estrogen synthesizing capacity,
which is the time required by the body to replenish its
enzyme levels. It seems logical based on structure and
action that the same thing occurs with testolactone.
Although testolactone is technically steroidal in structure,
it offers no anabolic or androgenic effect to its user. This is
because it does not possess the traits necessary to bind
and activate the androgen receptor, namely an active 17beta-
hydroxyl group. In fact, its D ring is an unusual sixmembered
lactone ring, and not the normal fivemembered
carboxylic ring that testosterone and its
derivatives normally possess. This is likely where
testolactone got its name, which may be short for
testosterone-lactone. Studies actually suggest this
steroidal drug possesses some level of anti-androgenic
action, which likely occurs via competitive inhibition of the
cellular androgen receptor. Regardless of this,
testolactone has been included in the u.S. controlled
substance list as an anabolic/androgenic steroid. For the
purposes of this reference book it will remain classified as
an anti-estrogenic drug. Likewise, testolactone is used by
athletes and bodybuilders not to increase muscle mass
and performance, but to mitigate the estrogenic side
effects caused by certain anabolic/androgenic steroids.
Note that the level of aromatase inhibition produced with
testolactone is significantly lower than that produced by
the newer selective third generation inhibitors such as
anastrozole, letrozole, and exemestane. For example, one
study conducted in 1985 showed that 1,000 mg of
testolactone per day given to nine normal men for a period
of ten days suppressed serum estradiol levels by 250/0 .
Another using the same 1,000 mg dose noted a 500/0
reduction after six days of use. These numbers are lower
than what would be expected of the newer thirdgeneration
agents given the substantial estrogen
suppression figures they have produced during clinical
trials with women.
History:
Testolactone was first approved as a prescription drug by
the FDA back in 1970.lt was an early anti-estrogenic drug,
exhibiting a moderately pronounced effect but failing to
reach levels of high clinical success. As other more effective
medications began to surface for the treatment of breast
cancer, testolactone would not see the success its
developers likely planned for it. It would see production in
a small number of countries outside the U.S., most notably
Brazil, Germany, and Chile. It has since been discontinued in
all countries but the U.S., where the Teslac brand is still
available.
How Supplied:
Testolactone is most commonly supplied in tablets of 50
mg.
Structural Characteristics:
Testolactone is classified as a steroidal noncompetitive
irreversible steroidal aromatase inhibitor. It has the
chemical designation 13-hydroxy-3-oxo-13,17secoandrosta-
1 ,4-dien-17-oic acid [dgr ]-Iactone.
Side Effects:
Common side effects associated with the use of an
aromatase inhibitor include hot flashes, joint pain,
weakness, fatigue, mood changes, depression, high blood
pressure, swelling of the arms/legs, and headache. In 1999,
the FDA officially added malaise to the list of possible side
effects from this drug, reflecting something bodybuilders
had noticed for some time: low estrogen levels can lead to
lethargy, as this sex hormone plays an important role in the
functioning of the central nervous system. Aromatase
inhibitors may also decrease bone mineral density,.which
may lead to osteoporosis and an increase in fractures in
susceptible patients. Some individuals may also respond to
the medication with gastrointestinal side effects including
nausea and vomiting. Aromatase inhibitors can harm the
development of an unborn fetus, and should never be
taken or handled during pregnancy. When taken by men
(as an off-label use) to reduce estrogenicity during
prolonged periods of steroid treatment, aromatase
inhibitors may increase cardiovascular disease (CVD) risk
by retarding some beneficial properties of estrogen on
cholesterol values. Studies have demonstrated that when
an aromatizable steroid such as testosterone enanthate is
taken in conjunction with testolactone, suppression of
HDL (good) cholesterol levels becomes significantly more
pronounced. Since the estrogen receptor
agonist/antagonist Nolvadex® generally does not display
the same anti-estrogenic (negative) effect on cholesterol
values, it is usually favored over aromatase inhibitors for
estrogen maintenance by male bodybuilders and athletes
concerned with cardiovascular health.
Administration:
Testolactone is FDA approved as adjunctive therapy in the
palliative treatment of advanced or disseminated breast
cancer in postmenopausal women when hormonal
therapy is indicated. It may also be used in women who
were diagnosed as having had disseminated breast
carcinoma when premenopausal, in whom ovarian
function has been subsequently terminated. The
recommended dosage is 250 mg taken 4 times per day.
When used (off-label) for estrogen suppression in male
steroi,d users, a dosage of 250 mg (five tablets) is usually
ta ken per day.
Availability:
Testolactone is no longer commonly used in clinical
medicine, and consequently is not manufactured on a
large sale globally. Presently a small number of
testolactone preparations still exist, but are not commonly
diverted for sale on the black market given the very low
demand for the drug in this population.
