Good Read on Clomid vs. Nolvadex
Hey bros, i found this posted on another forum. ( INTIMID8OR3 )Really good reading.
OG
I have received a lot of heat lately about my
preference for Nolvadex over Clomid, which I hold for
all purposes of use (in the bodybuilding world
anyway); as an anti-estrogen, an HDL (good)
cholesterol-supporting drug, and as a
testosterone-stimulating compound. Most people use
Nolvadex to combat gynecomastia over Clomid anyway, so
that is an easy sell. And for cholesterol, well, most
bodybuilders unfortunately pay little attention to
this important issue, so by way of disinterest,
another easy opinion to discuss. But when it comes to
using Nolvadex for increasing endogenous testosterone
release, bodybuilders just do not want to hear it.
They only seem to want Clomid. I can only guess that
this is based on a long rooted misunderstanding of the
actions of the two drugs. In this article I would
therefore like to discuss the specifics for these two
agents, and explain clearly the usefulness of Nolvadex
for the specific purpose of increasing testosterone
production.
Clomid and Nolvadex
I am not sure how Clomid and Nolvadex became so
separated in the minds of bodybuilders. They certainly
should not be. Clomid and Nolvadex are both
anti-estrogens belonging to the same group of
triphenylethylene compounds. They are structurally
related and specifically classified as selective
estrogen receptor modulators (SERMs) with mixed
agonistic and antagonistic properties. This means that
in certain tissues they can block the effects of
estrogen, by altering the binding capacity of the
receptor, while in others they can act as actual
estrogens, activating the receptor. In men, both of
these drugs act as anti-estrogens in their capacity to
oppose the negative feedback of estrogens on the
hypothalamus and stimulate the heightened release of
GnRH (Gonadotropin Releasing Hormone). LH output by
the pituitary will be increased as a result, which in
turn can increase the level of testosterone by the
testes. Both drugs do this, but for some reason
bodybuilders persist in thinking that Clomid is the
only drug good at stimulating testosterone. What you
will find with a little investigation however is that
not only is Nolvadex useful for the same purpose, it
should actually be the preferred agent of the two.
Pituitary Sensitivity to GnRH
Studies conducted in the late 1970's at the University
of Ghent in Belgium make clear the advantages of using
Nolvadex instead of Clomid for increasing testosterone
levels (1). Here, researchers looked the effects of
Nolvadex and Clomid on the endocrine profiles of
normal men, as well as those suffering from low sperm
counts (oligospermia). For our purposes, the results
of these drugs on hormonally normal men are obviously
the most relevant. What was found, just in the early
parts of the study, was quite enlightening. Nolvadex,
used for 10 days at a dosage of 20mg daily, increased
serum testosterone levels to 142% of baseline, which
was on par with the effect of 150mg of Clomid daily
for the same duration (the testosterone increase was
slightly, but not significantly, better for Clomid).
We must remember though that this is the effect of
three 50mg tablets of Clomid. With the price of both a
50mg Clomid and 20mg Nolvadex typically very similar,
we are already seeing a cost vs. results discrepancy
forming that strongly favors the Nolvadex side.
But something more interesting is happening.
Researchers were also conducting GnRH stimulation
tests before and after various points of treatment
with Nolvadex and Clomid, and the two drugs had
markedly different results. These tests involved
infusing patients with 100mcg of GnRH and measuring
the output of pituitary LH in response. The focus of
this test is to see how sensitive the pituitary is to
Gonadotropin Releasing Hormone. The more sensitive the
pituitary, the more LH will be released. The tests
showed that after ten days of treatment with Nolvadex,
pituitary sensitivity to GnRH increased slightly
compared to pre-treated values. This is contrast to 10
days of treatment with 150mg Clomid, which was shown
to consistently DECREASE pituitary sensitivity to GnRH
(more LH was released before treatment). As the study
with Nolvadex progresses to 6 weeks, pituitary
sensitivity to GnRH was significantly higher than
pre-treated or 10-day levels. At this point the same
20mg dosage was also raising testosterone and LH
levels to an average of 183% and 172% of base values,
respectively, which again is measurably higher than
what was noted 10 days into therapy. Within 10 days of
treatment Clomid is already exerting an effect that is
causing the pituitary to become slightly desensitized
to GnRH, while prolonged use of Nolvadex serves only
to increase pituitary sensitivity to this hormone.
That is not to say Clomid won't increase testosterone
if taken for the same 6 week time period. Quite the
opposite is true. But we are, however, noticing an
advantage in Nolvadex.
The Estrogen Clomid
The above discrepancies are likely explained by
differences in the estrogenic nature of the two
compounds. The researchers' clearly support this
theory when commenting in their paper, "The difference
in response might be attributable to the weak
intrinsic estrogenic effect of Clomid, which in this
study manifested itself by an increase in transcortin
and testosterone/estradiol-binding globulin [SHBG]
levels; this increase was not observed after tamoxifen
treatment". In reviewing other theories later in the
paper, such as interference by increased androgen or
estrogen levels, they persist in noting that increases
in these hormones were similar with both drug
treatments, and state that," …a role of the intrinsic
estrogenic activity of Clomid which is practically
absent in Tamoxifen seems the most probable
explanation".
Although these two are related anti-estrogens, they
appear to act very differently at different sites of
action. Nolvadex seems to be strongly anti-estrogenic
at both the hypothalamus and pituitary, which is in
contrast to Clomid, which although a strong
anti-estrogen at the hypothalamus, seems to exhibit
weak estrogenic activity at the pituitary. To find
further support for this we can look at an in-vitro
animal study published in the American Journal of
Physiology in February 1981 (2). This paper looks at
the effects of Clomid and Nolvadex on the GnRH
stimulated release of LH from cultured rat pituitary
cells. In this paper, it was noted that incubating
cells with Clomid had a direct estrogenic effect on
cultured pituitary cell sensitivity, exerting a weaker
but still significant effect compared to estradiol.
Nolvadex on the other hand did not have any
significant effect on LH response. Furthermore it
mildly blocked the effects of estrogen when both were
incubated in the same culture.
Conclusion
To summarize the above research succinctly, Nolvadex
is the more purely anti-estrogenic of the two drugs,
at least where the HPTA
(Hypothalamic-Pituitary-Testicular Axis) is concerned.
This fact enables Nolvadex to offer the male
bodybuilder certain advantages over Clomid. This is
especially true at times when we are looking to
restore a balanced HPTA, and would not want to
desensitize the pituitary to GnRH. This could perhaps
slow recovery to some extent, as the pituitary would
require higher amounts of hypothalamic GnRH in the
presence of Clomid in order to get the same level of
LH stimulation.
Nolvadex also seems preferred from long-term use, for
those who find anti-estrogens effective enough at
raising testosterone levels to warrant using as
anabolics. Here Nolvadex would seem to provide a
better and more stable increase in testosterone
levels, and likely will offer a similar or greater
effect than Clomid for considerably less money. The
potential rise in SHBG levels with Clomid, supported
by other research (3), is also cause for concern, as
this might work to allow for comparably less free
active testosterone compared to Nolvadex as well.
Ultimately both drugs are effective anti-estrogens for
the prevention of gyno and elevation of endogenous
testosterone, however the above research provides
enough evidence for me to choose Nolvadex every time
