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by Bill Roberts - Testosterone, as the natural
product drug and one of the most widely used AAS,
is the most convenient choice for a reference drug
to which all others will be compared. And while
it is entirely possible to construct maximally-effective
steroid cycles without employing testosterone, most
do not do this, but instead use testosterone as
their foundation. Either approach can be entirely
sound.
As a bodybuilding drug, testosterone is almost
always used as an injectable ester, due to poor
oral bioavailability and the impracticality of high
dose transdermal or sublingual delivery. Testosterone
also is provided as an injectable suspension. Discussion
here is in reference to these injectable preparations.
Pharmacologically, testosterone acts both via
the androgen receptor and via other means. In practice,
it is found to combine synergistically both with
those anabolic steroids categorized as Class I and
those categorized as Class II, and therefore is
described as having mixed activity.
Particular properties of testosterone that are
of note include that it converts enzymatically both
to DHT and to estradiol (the most important of the
estrogens.)
While with normal levels of testosterone and
normal enzyme activity these conversions are in
fact desirable, with supraphysiological testosterone
levels caused by drug administration they can be
undesirable. DHT is at least three times more potent
(effective per milligram) than testosterone at the
androgen receptor (AR): therefore, in those tissues
which convert testosterone to DHT, there is effectively
three times as much androgen as elsewhere in the
body. Thus, whatever level of androgen is experienced
by the muscle tissue is effectively multiplied threefold
or more in the skin and in the prostate. This can
be excessive.
Dutasteride (Avodart) can be used to keep DHT
levels normalized despite heavy testosterone use.
Most users do not do this out of concern for excessively
reducing DHT, which may be a valid concern at full
label dosing, but which I do not think is a concern
with low-dose use (½ tab every other day) in the
context of a high-dose testosterone cycle.
Finasteride (Proscar) may be employed instead,
if one wishes to use a 5alpha-reductase inhibitor.
In this case, in the context of a high-dose testosterone
cycle, one tab (5 mg) of this drug per day is unlikely
to excessively decrease DHT.
Excess conversion to estrogen is another undesirable
occurrence since it contributes to inhibition of
the hypothalamic/pituitary/testicular axis (HPTA),
can cause or aggravate gynecomastia, can cause bloating,
and can give unfavorable fat pattern distribution.
This conversion can be controlled by use of aromatase
inhibitors such as Arimidex or letrozole, and/or
the effects of excess estradiol may be blocked in
relevant tissues by Clomid or Nolvadex.
Among the most significant differences of synthetic
AAS compared to testosterone is that they may avoid
either or both of these enzymatic conversions. In
the past, this was a very important advantage. However,
now that these conversions can be well-controlled,
high-dose testosterone need not have all the adverse
side effects that once inevitably accompanied its
use.
Testosterone used as the sole androgen is capable
of giving very effective results, particularly with
doses of one gram or more per week, and can give
substantial results with only 500 mg/week. If no
other drugs are used to control estrogen, however,
side effects such as gynecomastia are fairly likely.
Prostate enlargement, acne or worsening of acne,
and acceleration of male pattern baldness (for those
genetically susceptible to it) are more problematic
with testosterone – again, in the absence of enzymatic
control -- than with many synthetics because of
the effectively-higher androgen levels seen in these
tissues as a result of local conversion to the more-potent
DHT.
So, to minimize these effects, the choices for
a highly-effective cycle that is low in side effects
are to either control these enzymatic conversions
with ancillary compounds while using testosterone
at high dose; to instead use synthetics which do
not undergo these conversions; or to combine moderate
dose testosterone (100-200 mg/week) with synthetics.
An anti-aromatase is preferable in a testosterone
cycle to a SERM such as Clomid or Nolvadex for controlling
estrogen because the SERMs either do nothing towards
reducing effect of elevated estrogen in aggravating
or causing acne, or themselves contribute adversely.
Additionally, abnormally elevated estrogen levels
may be deleterious for other reasons.
With regard to inhibition of the hypothalamic/pituitary/testicular
axis (HPTA), 200 mg/week of injected testosterone
is approximately 2/3 to 3./4 suppressive, while
100 mg/week is about 50% suppressive. For this reason,
low dose testosterone use is not particularly efficient,
as natural production is already “worth” 100-200
mg/week, and this is mostly lost with the first
200 mg/week of injectable that is used. The particular
synthetics which are low-suppressive are, for this
reason, more efficient for low-dose use than is
testosterone.
In terms of planning HPTA recovery after a cycle,
for the above reason there is little point in beginning
post-cycle therapy (PCT) until testosterone levels
from the cycle have fallen to being commensurate
with use of no more than about 200 mg/week. So for
example, if using 800 mg/week, it would be advisable
to wait two half-lives. (After a number of days
equal to the half life, levels will drop to that
commensurate with 400 mg/week use, and after that
same number of days again levels will again fall
in half, now to levels to commensurate with 200
mg/week use.) So for example if the half-life of
the ester used were 5 days, one would wait till
10 days after the last injection to begin PCT, when
the drug in question is testosterone, due to the
particulars of its suppressive properties.
With use of an anti-aromatase, 600-750 mg/week
of injected testosterone is a good dosage range
for a novice. Without an anti-aromatase, it may
be preferred to limit usage to 500 mg/week, although
there can be risk of gynecomastia at doses even
as low as 200 mg/week if no anti-estrogen is used.
More advanced users may favor a gram per week. Still-higher
doses such as 2 grams per week generally provide
only a small further increment in performance, with
that generally being noticeable only if a plateau
has been reached at 1 gram per week. Amounts higher
than this are employed by some pro bodybuilders
but probably with only a slight further incremental
effect.
Injectable testosterone esters commonly used
for testosterone therapy:
-
Testosterone Enanthate: Chemical Formula
C7H14O2
Testosterone enanthate is one of the main forms
of testosterone prescribed in the United States.
It is a slow-acting ester with a release time
between 8-10 days. The name-brand of T-enanthate
available in the United States is called "Delatestryl,"
which is suspended in sesame oil. Testosterone
enanthate is typically injected anywhere between
once every week to once every three weeks.
Download Delatestryl Package Insert
-
Testosterone Cypionate: Chemical Formula
C8H14O2
Testosterone cypionate is the other main injectable
form of testosterone prescribed in the United
States. It is a slow-acting ester with a release
time between 8-10 days, similar to that of enanthate.
The name-brand of testosterone cypionate available
in the United States is called "Depo-Testosterone,"
which is suspended in cottonseed oil. Testosterone
cypionate is typically injected anywhere between
once every week to once every three weeks.
Download Depo-Testosterone Package Insert
- Sustanon 250
"Sustanon" is the brand name for a blend
of four testosterone esters: testosterone propionate
(C3H6O2), testosterone phenylpropionate (C9H10O2),
testosterone isocaproate (C6H12O2), and testosterone
decanoate (C10H20O2). It features both fast-acting
and slow-acting esters, and can be injected
anywhere from once every week to once every
four weeks. It is prescribed outside of the
United States.
-
Testosterone
Propionate: Chemical Formula C3H6O2
Testosterone propionate is a fast-acting ester
with a release time of 3-4 days. To keep blood
levels from fluctuating greatly, propionate
is usually injected between one to three times
a week. Some users also report that propionate
is a more painful injection, with swelling and
noticeable pain around the injection site. Brand
names of testosterone propionate include "Testovis"
and "Virormone."
-
Testosterone Phenylpropionate: Chemical
Formula C9H10O2
Testosterone phenylpropionate is a slow-acting
ester, with a release time of 1-3 weeks. A popular
name brand for T-phenylpropionate is "Testolent."
Testosterone phenylpropionate is also one of
the components of Sustanon and Omnadren.
- Omnadren
"Omnadren" is the brand name for a blend of
four testosterone esters: testosterone propionate
(C3H6O2), testosterone phenylpropionate (C9H10O2),
testosterone isocaproate (C6H12O2), and testosterone
decanoate (C10H20O2). In the past, Omnadren
consisted of a blend of different esters, but
now is essentially the same formula as Sustanon,
mentioned above. It features both fast-acting
and slow-acting esters, and can be injected
anywhere from once every week to once every
four weeks. It is sometimes prescribed in parts
of Europe.
-
Aqueous
Testosterone Suspension
In the United States, injectable aqueous (non-esterified)
testosterone is available, but it is very short-acting
(it is completely released in the system within
a matter of hours). The brand name for aqueous
testosterone suspension is "Aquaviron."
TRANSDERMAL TESTOSTERONE
Testosterone Patches
Testosterone Gels
- Androgel
Androgel is a clear, alcohol-based gel that
contains 1% non-esterified testosterone. It
is very fast-acting once it has been absorbed
by the skin, and so must be reapplied at 1-2
times daily to maintain T levels. It is available
in either unit-dose packets or multiple-dose
pumps. The unit dose packets contain either
25 mg or 50 mg of testosterone. Approximately
10% of the applied testosterone from the packets
is absorbed into the system, resulting in an
effective dose of 2.5 mg or 5.0 mg, respectively.
Androgel should be applied to clean, dry skin
and should not be applied to the genital area.
Application sites should be allowed to dry for
a few minutes prior to dressing. Hands should
be washed thoroughly with soap and water after
application.
In order to prevent transfer to another person,
clothing should be worn to cover the application
sites. If direct skin-to-skin contact with another
person is anticipated, the application sites
should be washed thoroughly with soap and water.
Users should wait at least 2 hours after applying
before showering or swimming; for optimal absorption,
it may be best to wait 5-6 hours.
Download AndroGel Package Insert
-
Testim
Testim, like Androgel, is a clear, alcohol-based
gel that contains 1% non-esterified testosterone.
It is very fast-acting once it has been absorbed
by the skin, and so must be reapplied at 1-2
times daily to maintain T levels. It is available
in 5.0g unit-dose tubes. A 5.0g unit dose tube
contains 50 mg of testosterone. Approximately
10% of the applied testosterone from the tube
is absorbed into the system, resulting in an
effective dose of 5.0 mg.
Testim should be applied to clean, dry skin--
preferably to the shoulders and/or upper arms.
It should not be applied to the genitals or
to the abdomen. Application sites should be
allowed to dry for a few minutes prior to dressing.
Hands should be washed thoroughly with soap
and water after application.
In order to prevent transfer to another person,
clothing should be worn to cover the application
sites. If direct skin-to-skin contact with another
person is anticipated, the application sites
should be washed thoroughly with soap and water.
Users should wait at least 2 hours after applying
before showering or swimming; for optimal absorption,
it may be best to wait 5-6 hours.
ORAL TESTOSTERONE
- Methyltestosterone
(C-17 Alpha Alkylated Testosterone)
Methyltestosterone is one of the earliest available
oral testosterones. Its chemical structure is
the hormone testosterone with an added methyl
group at the c-17 alpha position of the molecule.
Brand names include "Metesto," "Methitest,"
"Testred," "Oreton Methyl," and "Android."
- Testosterone Undecanoate
Testosterone undecanoate is not a c-17 alpha
alkylated hormone. Therefore, it is considered
a safer oral form of testosterone. Additionally,
it is absorbed through the small intestine into
the lymphatic system, posing less burden on
the liver. Brand names for testosterone undecanoate
include "Andriol," "Androxon,"
"Understor," "Restandol," and
"Restinsol." It is not available in the
United States.
One disadvantage of orally administered undecanoate
is that it is eliminated from the body very
quickly, usually in 3-4 hours. Thus, frequent
administration is necessary-- usually between
3-6 capsules a day. This can prove to be quite
expensive when compared to injectable testosterone.
Download
Andriol Package Insert
BUCCAL TESTOSTERONE
- Buccal
In 2003, the FDA approved a sustained-release
buccal testosterone tablet called "Striant."
It acts by adhering to the buccal mucosa (the
small depression in the mouth where the gum
meets the upper lip above the incisor teeth).
Once applied, the tablet softens and delivers
testosterone through the buccal mucosa, where
it is then absorbed directly into the bloodstream,
bypassing the gastrointestinal system and liver.
The recommended dosage for Striant is to replace
the tablet about every 12 hours, though a different
dosing schedule or number of tablets might be
required depending on the needs of the patient.
Download Striant Package Insert
SUBCUTANEOUS TESTOSTERONE PELLET
- Another relatively new form of testosterone
delivery is via a pellet of pure, crystalline
testosterone implanted beneath the skin. The
pellets are about the size of a grain of rice,
and are typically placed in the buttocks or
abdomen. The insertion of the pellets is a quick
procedure, usually done under local anesthesia.
Pellets are usually replaced after 3-4 months.
"Testopel" is a brand name for testosterone
pellets in the United States.
A 200 mg testosterone pellet releases testosterone
at a steady rate of 1-3 mg per day. Several
pellets can be inserted at the same time to
increase dosage.
Some users have reported problems with the pellets
working their way out from under the skin.
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Trivial name
|
Testosterone [USAN:INN]
(base)
|
| Chemical name |
17ß-hydroxyandrost-4-en-3-one
|
| Systematic Name |
(8S,9S,10R,13S,14S,17S)-17-hydroxy-10,13-dimethyl-1,2,6,7,8,9,11,12,14,15,16,17-dodecahydrocyclopenta[a]phenanthren-3-one
|
| Index name |
Androst-4-en-17beta-ol-3-one |
| CAS number |
58-22-0 |
| Empirical formula |
C19-H28-O2 |
| Merck Index Number |
Merck 11, 9109 |
| Molecular weight |
288.424 g/mol |
| Pregnancy category |
X |
| Legal status |
Prescription
only (US); DEA Schedule III (US) |
| Routes of administration |
Various |
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Last Revised: October
5, 2009
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