In this article, we will try to resolve doubts about the choice between two drugs, as well as find differences: clomid or nolvadex.
Clomiphene citrate (available in pharmacies under the brand name Clomid) and tamoxifen (trade name Nolvadex) are antiestrogens belonging to the same group of triphenylethylenes. They are structurally similar and classified as selective estrogen receptor modulators with mixed agonistic and antagonistic properties. This means that in certain tissues they block the action of estrogen by binding to receptors, while in other tissues they can act like real estrogen by activating receptors. In men, both drugs act as antiestrogens in their ability to interfere with the negative feedback of estrogens to the hypothalamus and stimulate increased production of GnRH (gonadoliberin). As a result, the production of the luteinizing hormone prolactin and the follicle-stimulating hormone by the pituitary gland will be increased, which in turn can increase the production of testosterone by the testicles. Both drugs do this, but for some reason, bodybuilders continue to think that only clomid is good for stimulating testosterone.
Research conducted in the late 70s at the University of Ghent in Belgium clarifies the benefits of nolvadex over clomid in increasing testosterone levels. The researchers looked at the effect of nolvadex and clomid on the endocrine system of healthy men, as well as those who suffered from a small number of sperm (oligospermia). It was also found that Nolvadex, when used for 10 days at a dosage of 20 mg per day, increased serum testosterone levels by 142% from the initial level, which was comparable to the effect of 150 mg of clomid per day over the same time period (the increase in testosterone levels was slightly, but not significantly, more with clomid). We must remember that this is the effect of three 50mg clomid tablets. With approximately the same price of 50mg of clomid and 20mg of nolvadex, we already see a difference in the price / result ratio in favor of nolvadex.
Differences between clomid and nolvadex
Clomid acts on estrogen receptors in the pituitary gland and ovaries. By binding estrogen receptors in the pituitary gland, clomid breaks the negative feedback mechanism, i.e. if usually estrogens, acting on the pituitary gland, reduce the production of FSH and LH, this does not happen when taking clomid. Clomid does not directly affect the level of estrogens in the blood.
Nolvadex also does not affect the level of estrogens in the blood, because its mechanism of action is also reduced to the blockade of estrogen receptors, including in the pituitary gland. However, clomid is a more selective (selective) blocker, while nolvadex is less selective. While clomid binds to estrogen receptors primarily in the pituitary gland and testicles, nolvadex binds to them almost throughout the body. The exception is bone tissue, where clomid and tamoxifen, on the contrary, activate estrogen receptors.
Thus, clomid acts as an antagonist of estrogens and eliminates their depressing effect on the hypothalamus and pituitary gland, contributing to a faster recovery of their function. Nolvadex blocks receptors in almost all tissues, and also helps the body begin to restore its own testosterone. It is important to note that nolvadex is able to block estrogen receptors in the pituitary gland to a lesser extent than clomid.
Clomiphene and tamoxifen do not affect the metabolism of estrogenic hormones, so against the background of taking these drugs, estrogens continue to be destroyed by liver enzymes, and do not accumulate in the body.
Tamoxifen has disadvantages: it is quite toxic (sometimes it is manifested by loss of appetite and nausea, and the risk of thrombosis increases). Tamoxifen increases the number of progesterone receptors, so it can not be used if the course is based on progestin drugs (nandrolone, trenbolone). In this case, you should use clomiphene.
Clomid: common fault
- Both drugs inhibit the production of insulin-like growth factor-1
- Directly inhibit the function of the testicles
- Increase sex hormone binding globulin
- Increase the concentration of estrogens several times
- Cause visual impairment with prolonged use
- In some cases, when using Clomid for a month at a dosage of 25 mg per day, after 2 weeks after the end of the course, there was a decrease in total testosterone by 16-17% (while there was a decrease in estradiol by 13.5%)
- It is important to understand that in some people, the pituitary-hypothalamus-testicular arch (GGT) may not respond to stimulation with Clomid (clomiphene) or nolvadex (tamoxifen)
It is most rational to use aromatase inhibitors during the course, among which Proviron is especially popular, since this drug does not negatively affect the secretion of growth hormone and increases the concentration of anabolic hormones in the blood by suppressing aromatization. In the last week of the course and 2 weeks after, Tamoxifen should be used as the main component of PCT in the absence of Proviron, the start of Nolvadex administration falls on the 2nd week of the steroid cycle, and ends 2-3 weeks after the end of the cycle, the average dose is 10-20 mg per day. I would like to pay special attention to the common misconception that antiestrogens are recommended to drink after a cycle. The level of estrogens increases at the end of the first week of the cycle, so it is from this moment that you need to start taking!