While practically similar compounds in structure, few people ever really consider Clomid and Nolva to be similar. Its not just a common myth in steroid circles, but even in the medical community. This misconception originates from their completely different uses. Nolvadex is most commonly used for the treatment of breast cancer in women, while clomid is generally considered a fertility aid. In bodybuilding circles, from day one, clomid has generally been used as post-cycle therapy and Nolvadex as an anti-estrogen.
But as I intend to demonstrate this is in essence the same. I believe the myth to have originated because Nolva is clearly a more powerful anti-estrogen, and the people selling clomid needed another angle to sell the stuff, so it was mostly used as a post-cycle aid. But few users really understand how clomid (and also Nolvadex, logically) works to bring back natural testosterone in the body after the conclusion of a cycle of androgenic anabolic steroids. After a cycle is over, the level of androgens in the body drop drastically. The body compensates with an overproduction of estrogen to keep steroid levels up. Estrogen as well inhibits the production of natural testosterone, and in the period between the return of natural testosterone and the end of a cycle, a lot of mass is lost. So its in everybody's best interest to bring back natural test as soon as humanly possible. Clomid and Nolvadex will reduce the post-cycle estrogen, so that a steroid deficiency is constated and the hypothalamus is stimulated to regenerate natural testosterone production in the body. That's basically how the mechanism works, nothing more, nothing less.
Both compounds are structurally alike, classified as triphenylethylenes. Nolvadex is clearly the stronger component of the two as it can achieve better results in decreasing overall estrogen with 20-40 mg a day, than clomid can in doses of 100-150 mg a day. A noteworthy difference. Triphenylethylenes are very mild estrogens that do not exert a lot, if any activity at the estrogen receptor, but are still highly attracted to it. As such they will occupy the receptor and keep it from binding estrogens. This means they do not actively work to reduce estrogen in the body like Proviron, Viratase or arimidex would (by competing for the aromatase enzyme), but that it blocks the receptor so that any estrogen in the body is basically inert, because it has no receptor to bind to.
This has advantages and disadvantages. The disadvantage is that when use is discontinued, the estrogen level is still the same and new problems will develop much sooner. The advantage is that it works much faster and has results sooner than with an aromatase blocker like Proviron or arimidex. Therefor, when problems such as gynocomastia occur during a cycle of steroids one will usually start 20 mg/day of Nolva or 100 mg/day of clomid straight away, in conjunction with some Proviron or arimidex. The proviron or arimidex will actively reduce estrogen while the clomid or Nolvadex will solve your ongoing problem straight away. This way, when use is discontinued there is no immediate rebound.
So which one should you use? Well personally, I'd have to say Nolvadex. Both as an on-cycle anti-estrogen and a post-cycle therapy. As an anti-estrogen its simply much stronger, demonstrated by the fact that better results are obtained with 20-40 mg than with 100-150 mg of clomid. For post-cycle, this plays a key role as well. It deactivates rebound estrogen much faster and more effective. But most importantly, Nolvadex has a direct influence on bringing back natural testosterone, where as clomid may actually have a slight negative influence. The reason being that Tamoxifen (as in Nolvadex) seems to increase the responsiveness of LH (luteinizing hormone) to GnRH (gonadtropin releasing hormone), whereas clomid seems to decrease the responsiveness a bit.
Another noteworthy fact about Nolvadex is that it acts more potently as an estrogen in the liver. As you remember, I mentioned that clomiphene and tamoxifen are basically weak estrogens. Well, tamoxifen is apparently still quite potent in the liver. This offers us the positive benefits of this hormone in the liver, while avoiding its negative effects elsewhere in the body. As such Nolvadex can have a very positive impact on negative cholesterol levels in the body, and therefore too should be considered a better choice than clomid. It will not solve the problem of bad cholesterol levels during Steroid use, but will help to contain the problem to a larger degree.
Another reason why promote the use of Nolvadex over Clomid post-cycle (as if being 3-4 times stronger and having more of a direct effect on restoring natural test wasn't enough) is because it's a lot safer. Not just because it improves lipid profiles, but also because it simply doesn't have the intrinsic side-effects that Clomid has. Clomid causes more acne for sure, but that's mainly because you need to use a 3-4 times higher dose. But Clomid seems to also affect the eyesight. Long-term clomid therapy causes irreversible changes in eyesight in users. Irreversible. For me that alone is reason enough to prefer Nolvadex.
Lastly, one should be aware that use of these compounds can reduce the gains made on steroids. Nolvadex more so than clomid, simply because it is stronger. Estrogen is responsible for a number of anabolic factors such as increasing growth hormone output, upgrading the androgen receptor and improving glucose utilization. This is why aromatizing steroids like testosterone are still best suited for maximum muscle gain. When reducing the estrogen levels, we therefore reduce the potential gains being made. For this reason one may opt to try clomid during a cycle instead of Nolvadex. Although I would imagine that the problem that needed solved would be of more concern, in which case Nolva remains the weapon of choice. It's a plain fact that there is a high correlation between gains and side-effects. Either you go for maximum gains and tolerate the side-effects, or you reduce the side-effects, and with it the gains. That's life, nothing is free.
If problems of Gynocomastia or other estrogen related symptoms tend to pop up during a cycle the use of 20-30 mg of Nolvadex or 100 mg of Clomid daily should easily contain the problem, and be used until a few days after the problem subsides. For best results and the least amount of problems upon cessation it is best stacked with Proviron (50 mg) or arimidex (0.5 mg) for this duration as well. Its not advised that these products be ran concomitantly with the steroid for the entire duration of the stack, as this will reduce your gains. Instead cease the usage of anti-estrogens once the problem is contained, and should the problem resurface, simply recommence the use of the products in the same manner as described above.
Once a cycle of steroids is concluded one should always initiate a post-cycle therapy to help bring back natural testosterone as soon as possible. This will help you to retain the mass you gained. How this is done depends highly on the type of steroid used. If only orals were used, therapy should start immediately, even the last day of the stack. If short-acting esters or water-based injectables were used, therapy should commence within 4-7 days after last injection, and if long-acting esters were used then it should commence 1.5 to 2 weeks after the last injection was given. The length of the therapy will vary as well, from 3-5 weeks. The longer acting the product was, the longer therapy should be continued to make sure all suppressive factors are cleared before use of Clomid/Nolvadex is discontinued.
For best results, it is best stacked with HCG (Human Chorionic gonadotrophin), which functions as an LH analog and can help bring testicle size back up. HCG use starts the last week of a cycle, and on from there every 5-6 days (usually 1500-3000 IU) and discontinued 1.5 to weeks prior to the cessation of Nolvadex/clomid. The reason being that HCG itself is also suppressive of natural testosterone and should be out of the body before therapy is over, or it will inhibit natural testicle function. But I can not stress enough that HCG possibly plays a more important role in post-cycle therapy than clomid/Nolvadex. For Clomid and Nolvadex, doses are usually tapered down. Its best to start with 40-50 mg of Nolvadex or 150 mg of Clomid for the first week or the first two weeks, and then finish the program with 20-25 mg of Nolvadex or 100 mg of Clomid for an additional two weeks.