How Clomid Works in Men

April 28th, 2010 § 934 comments

With the suspension of Cincinnati Reds pitcher Edinson Volquez for performance enhancing drug use and a swirl of rumors that the agent involved was clomiphene (also known as Clomid,) I thought it timely to write about how clomiphene works and how it’s used. From what I read on the internets, there is an enormous amount of misinformation floating around out there.

To understand how clomiphene works, you need to know how the pituitary controls the making of testosterone in the testis. Testosterone is made by Leydig cells in the testis, which I explained in my last post. The pituitary releases a hormone called luteinizing hormone (“LH”) that stimulates the Leydig cells to make testosterone. Testosterone is converted to the female hormone estrogen, (which I also explained in my last post,) and estrogen tells the pituitary to stop making more LH. This kind of negative feedback system is common when it comes to how hormones work. It’s just like a thermostat and heater. As the room gets warmer, the thermostat sends less electricity to the heater. When the room gets colder, the thermostat sends more electricity to the heater.

LH testosterone.png

Clomiphene works by blocking estrogen at the pituitary. The pituitary sees less estrogen, and makes more LH. More LH means that the Leydig cells in the testis make more testosterone.

As I explained in my last post, giving testosterone to a man does just the opposite. The pituitary thinks that the testis is making plenty of testosterone, and LH falls. As a result, the testis stops making testosterone, and the usually high levels of testosterone in the testis fall to the lower level in the blood.

So clomiphene is a way to increase testosterone in the blood and the testis at the same time. It preserves testis size and function while increasing blood testosterone.

Unfortunately, clomiphene is not FDA approved for use in the male. Like most of the medications that we use to treat male fertility, the pharmaceutical company that originally sought approval by the FDA did it for women. Clomiphene is now generic, and it’s unlikely that anyone will pony up the hundreds of millions of dollars necessary to get it approved for the male. That’s the bad news. The good news is that it means that this medication is fairly inexpensive, cheaper than most forms of prescription testosterone. Can a doctor prescribe clomiphene for a man? Yes. It’s “off label”, meaning that it’s not FDA approved for use in men.

As a medication, clomiphene is usually well tolerated by men. In my experience, most patients don’t feel anything as their testosterone rises. Those that do feel an increase in energy, sex drive, and muscle mass, especially if they work out. Very rarely I’ve had patients report that they feel too aggressive, or too angry. Very very rarely (twice in the last 20 years) I’ve had patients report visual changes. That’s worrisome, as the pituitary is near the optic nerve in the brain, and visual changes suggests that the pituitary may be changing in size. Because the skull is a closed space, it’s alarming if anything in the brain changes in size. In the last twenty years, I’ve also had two patients who had breast enlargement (called “gynecomastia”) while using clomiphene. Needless to say, for any of these problematic side effects, the clomiphene is discontinued.

So that’s the story with clomiphene. It can be used in the male, either for fertility or low testosterone levels. It’s an off label prescription drug. It works, and is usually well tolerated by men who take it.

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§ 934 Responses to How Clomid Works in Men"

  • Amid says:

    Hey Doc !

    I wanted to know if someone takes too much clomid regulary, will it cause the testosterone to keep on increasing(and therefore cause man boobs, excess facial hair and huge libido ?) or does the body respond by decresing production of testosterone, if someone kept on taking clomid at above normal frequency and amount ?

  • les says:

    i am under dr care now,and take 2cc of testrone every month or 2 times amonth.problem is sexaul performance.usually is to quick and can,t preforme for a long time after. what can i use to enhance longer and better for my wife.or at least start over 10or 15 minutes later. thanks, les

    • maledoc says:

      I’m sorry, Les, but I can’t answer personal questions about your own health. Please read the FAQ.

    • Dan says:

      I’m 34 and had low testosterone for the past couple of years. Quick finish and longer recuparation periods is usually a problem. I don’t have ED problems but taking ED medication gives me the boost I want in bed. I take 5-10mg of Cialis on the weekends and my sex life gets rejuvinated during the weekend.

  • Jessica says:

    Good Afternoon
    My husband recently started taking Clomid for fertility. He has been taking about 6 weeks now, 1/2 tablet a day. It did increase his T from 440 to 517, but his FSH also went up from 8 to 17! Is this normal? Is that too high?

  • GB says:

    I’ve seen you describe how long it takes for clomid to affect both testosterone levels and then sperm production later. My question is, is there a typical amount of time that clomid will maintain or build on these positive effects before those levels either plateau or begin to reverse? Basically, how long after it begins to work does it stop working or become less effective?


    • maledoc says:

      For men with low testosterone, clomiphene can be prescribed. The man’s doctor should monitor his testosterone level, which typically rises quickly within a week or two. For sperm production, because that takes two months or more, it can take several months before an effect is seen. And because sperm counts vary widely in any individual man, sperm counts can go up and down on treatment. These effects depend on the individual man, and should be monitored by his physician.

      • patientmom says:

        Is it correct to assume if testosterone level doesn’t rise quickly then clomiphene is not effective?

  • sunny dade says:

    i just ant to say and to ask my ? i want to know what would happen if i was taking it and him at the same he has low testosterone levels and i have a problem getting pregnant well i hope i get the answer i want to here o yes and could it be taking if he has heart problems his dr. wants me to do research lol i should of been a dr.

  • Kevin says:

    i have been diagnosed with pituitary failure as my Fh levels were extremely low, tesosterone level was a 65. I am a natural competitng bodybulder , well was until this health issue, my question is i was fine before i got rear ended in a car accident as a Tractor Trailer rear ended me, causing a concussion. Can this brain injury have caused my pituitary issue?

  • joe says:

    Hi doctor,
    I am grateful for this blog there is a lot of bad information out there. One issue I am confused with is the different opinions on what dosage of clomid to take. Some websites suggest taking a higher dosage like 300mg for the first week or so then tappering down. I know you mentioned in one of your blogs that you usually prescribe 25mg at first and then go up if needed. Is this a safer approach?Would a higher dose work faster at increasing testosterone?

    • maledoc says:

      Hi Joe, I can’t really comment on how other doctors prescribe clomiphene, and I’ve put what I do on this blog. I’d really encourage you to read the rest of the blog, as there’s a lot of information here. Importantly, any man taking clomiphene should be under a doctor’s care.

      • joe says:

        Thanks doc,the reason I asked is because my endocrinologist just perscribed clomid 50mg a day for me. He said that he doesnt have much expierience in perscribing clomid and Im not sure if I should ask him to start me on a smaller dose.

  • michelle says:

    If no blockage in a men but no sperm are ejaculated but being produced, could that be cause by low T?

  • Oliver says:

    Hi, I was just wandering if I’m correct in thinking the gynecomastia was caused by too low oestrogen, and more importantly, how low oestrogen causes gynecomastia. Any help, though especially in responce to the latter question, wouldbe greatly appreciated.

  • Scott says:

    Greetings and Happy New Year!
    In males with Low T, in addition to all the standard blood tests do you also routinely test for sleep apnea prior to making the determination to prescribe Clomid? In your experience, how severely can sleep apnea — in and of itself — occlude testosterone production? On a related note, how severely can an irregular sleep schedule impact testosterone production?
    Thank you,

    • andrew says:

      I have the same question like Scott. I have RLS and just went for a sleep study as my insomnia may also have to do with sleep apnea. I’m curios to find out if you are aware of any studies for the relationship of sleep apnea, RLS and azoospermia (due to low FSH and low T)

    • maledoc says:

      Testing for sleep apnea depends on the individual patient. Your question about sleep problems affecting testosterone is a good one, and that too depends on the individual man.

  • plok says:

    Doc gud day i have question bout clomid i have took taht med when me. And my wfe were trying to conceive our first baby id taken clomid for 2months before and also my wife coz she diagnose to have pcos by her obgyne we had a baby by then and now he is 2 yr old were trying to have another baby til now but still theres none we.wwnt bacl to her ob and told us her pcos are gone but i discontinued taking clomid.doc must i continue taking clomid in order to impregnate my wife ialso was diag.nose to have low sperm count.before tnx.

  • Robert1984 says:

    I have experience with Low testosterone and experience with taking Clomid to treat it. I am currently being treated by an endocrinologist who pretty much says the same things that you say about how and when you treat men with Low T with Clomid.

    I am asking this question only because I am interested in researching how men react to taking Clomid.

    I am confused as to why Clomid kills Labido in some men to the point were their sex drive is worse that in was before taking Clomid. Especially in men who’s blood lab results look as if the man has responded good to Clomid treatment. Do you have any explanations as to why this may be?

    Does Clomid do more than block estrogen at the pituitary? Does it β€œact” as an estrogen in other ways that could possibly explain this?

    • maledoc says:

      I’m sorry, Robert, but I can’t answer personal questions about your own health. Please read the FAQ.

    • I see this often with patients that come in frustrated with the ‘side effects’ of clomid. The drop in libido I see occasionally.

      I wonder if what is happening is just an over-aromatization of testosterone to estrogen. Lots of things can be the cause – Zn deficiency, lousy diet, too much body fat. Cruciferous veggies are good, esp broccoli, but if taking clomid I don’t think eating a ton of broccoli is enough to override the effects of coversion.


      • maledoc says:

        One way to determine whether the estradiol is elevated is to measure it. Libido is complex, and is affected by many factors beyond the endocrine system.

  • Nick says:

    Hello Doctor,

    What are the effects of Clomiphene after it is stopped? Are the changes permanent? Are any increases in testosterone production maintained, or do they diminish over time as the body adapts to lowering of estrogen levels?

    Also, comparing Clomiphene to direct testosterone intake for men with with low T, which would you say is safer long term?

  • Brian says:

    Can this drug prevent or reverse man boobs?

  • Steve says:

    Doc, does the increase in testosterone production resulting from use of this drug cause a greater risk of things like prostate or testicular cancers? Thanks.

  • Alex says:

    I have heard that zinc and vitamin c will also improve testosterone levels, is this true?

  • abdoulaye diallo says:

    i have a low count of sperm.and need to have baby please help./.

  • James Shepperd says:

    Hello Dr.,
    Is there any published evidence that you may have come across relating to ocular toxicity and the use of clomid? I’ve read an offhand reference to the subject but currently doubtful about any related direct evidence.
    Any updates on your experience with vision related issues and clomiphene? Over the 20yrs what kinds of numbers of male patients have you helped with clomiphene treatments?
    In discussions and analysis with peers does it appear that the low incidence of vision related side effects may be related to changes with pituitary glandular size.
    Thank you for the interesting blog.

    • maledoc says:

      Hi James, read through this post, its comments and the other posts on the blog. I talk about optical effects and clomiphene a bit.

  • Hannah says:

    Does taking Clomid necessarily decrease sperm count? I have read that taking Androgel, or using T injections dramatically decreases sperm count. There are many conflicting sites with information and I wondered if you had an answer! Thank you!

    • maledoc says:

      Clomiphene doesn’t typically decrease sperm count. There are many posts on this blog about how it works, how it’s used and its effects. You may want to read through the rest of this blog.

  • John Manley says:

    In have read the post and all the comments but have not seen any information on the typical duration that this drug is prescribed. Is it temporary or is it an on going treatment. Can it be used as an alteritive to testosterone treatment in those who have a deficiency?

  • Bill says:

    Hi doc

    Great blog!

    I am interested to know what your opinion is of using human chorionic gonadotropin as another alternative to endogenous testosterone for the low testosterone chap?

    Maybe this question deserves a new thread!?



  • Susan says:

    Can you please comment on the differences between Clomid and Nolvadex in restoring testosterone loss? Thank you.

    • maledoc says:

      I have been asked and have answered that question a number of times. Please read through the comments on this post, and the rest of the posts on this blog. My blog isn’t only this one post!

  • Petrus says:

    Your emails subscription link says “unsubscribe” shouldn’t it be “subscribe”?

    • maledoc says:

      That means that you’ve subscribed to my email list πŸ™‚ I haven’t sent out any emails. Someday I may, and you’ll be the first to get them!

  • tricia says:

    Are the chances of multiple births increased while men use clomid?

    • maledoc says:

      I’m fairly sure I’ve already answered this question, so please read through the rest of the comments and other posts on this blog. But the short answer is, no. Clomiphene may cause more eggs to be released in the female resulting in multiple births, but making more sperm does not achieve that effect.

  • RWH says:

    Hello, I was recently diagnosed with lowT. My levels were 142. My Dr immediately started me on test cyp injections every 2 weeks. I guess my main concern is that we went straight to treatment without investigating what is causing the problem. Are there other tests other than just blood work that might identify the cause and thus open up different treatment options?

  • just asking says:

    after reading through this page, i dont think you could answer any of my questions, you will either say you cant answer it or go look in my blog. dont want to wast my time reading useless info so i will go some were the person will realy help.

    • maledoc says:

      If you’re asking questions about your personal health that I can’t answer on a blog, then it’s really great that you will go somewhere where a doctor in person can really help!

  • chris says:

    Has there been any research or studies showing liver toxicity relating to clomid use in men? If so, can you comment or point to this information?

    Thank You

  • Eva says:

    Clomid was not successful for my husband, but I have been doing research on Gonad F and Menotropins. What are your opinion on the pros and cons of these drugs?

  • Mike says:

    Are you aware of any studies or data regarding long-term use of clomid to treat testosterone deficiency vs. depot injection? I’ve asked two doctors and they are very uninformed on clomid in general, much less for using it in men.

    • maledoc says:

      That’s a really great question, Mike, and unfortunately we don’t have any long term data on the use of clomiphene in men. Because it would take years, it would be an expensive study, and as clomiphene is generic, there’s no financial interest from a drug company that would fund it. That leaves agencies such as the National Institutes of Health, and hopefully at some point it will become a funding priority.

  • Alex says:

    Hi! You said that most of your patients don’t notice any change while their testosterone levels increase. So if one’s low energy and low libido because of low testosterone levels, shouldn’t clomiphene correct this?

  • Pierre says:

    Hello Dr Niederberger,
    I’ve read in different place that on the contrary of drugs like Arimidex or Femara that block the aromatase enzyme and therefore block the production of estrogen from aromatisation, Clomid blocks the estrogen receptors but do not block the “manufacturing” of estrogen. There it makes sense that you might have more estrogen in your bloodstream but that cannot go to their receptors. So my first question is if there cannot be a huge rebound effect when you stop taking Clomid with all those free estrogen with their receptors not blocked anymore and this brings my second question that is if it’s not preferable to enhance testosterone in Men to use Arimidex, Femara or yet Formestane. And if not, is it because of the side effects that can be more serious?

    Thank you et best regards!


    • maledoc says:

      Great questions, Pierre. I haven’t observed a “rebound effect” in clinical practice: it seems, with occasional exceptions, that the endocrine assays return to their pre-treatment levels. I am cautious to use an aromatase inhibitor like anastrozole as first-line therapy, as a certain amount of estradiol may be necessary for health in the male, including bone density and the prostate.

  • Pierre says:

    Dr Niederberger, thanks for your kind and interesting answer.

  • Danny says:

    hi doc, I read that Anastrazole is sometimes used if clomid causes estrogen levels to be too high.
    What are some possible problems that could happen if Clomid and Anastrazole are used together?

  • danny says:

    The reason i ask is because my endocrinologist put me on 25mg of clomid and in one month my testosterone went from 90 to 580 and sperm count and motility improved significantly as well. My only concern is that my estradol level increased from 11 to 32, which i was told was still in the normal range just in the higher range. Im hesitant about going off the clomid completely and going on anastrazole. My endocrinologist said a small dose of anastrazole every other day along with the 25mg of clomid shouldnt be a problem but im second guessing this option. Have you personally seen any problems with this?

  • Ned says:

    After clomid is discontinued, will an individuals testosterone remain at the same level, or will it drop back down to where it was?

  • Ben says:


    I understand how clomid works in men while they are taking it. Is there any evidence or studies that have shown it to keep T levels at a higher level after the dosage has stopped?

  • joe says:

    what is the difference between clomid and nolvadex ? i heard that nolvadex is better at preventing gyno, is that true?

    • maledoc says:

      Nolvadex is tamxoifen, and works in a similar way as Clomid. There’s just more data on Clomid so far in men. I’m assuming that “gyno” means gynecomastia in men. To my knowledge, there aren’t any controlled studies showing that one ore the other is better in preventing that side effect. If the estrogen becomes too elevated, other drugs, like anastrozole, can be used instead.

  • Bahraimi says:

    All Hormones are in the normal range but sperm count Zero and some time shows very very sperms (2) , My Doc write prescription for me:

    -choriomon 5000iui Injection per week for 3 months
    – Clomid One tab for 3 months.

    Is that right to increase sperm counts >>>>I need your advise

  • Bahraimi says:

    Thanks Doc…. i would like to know one thing Doc ! Plz Is it oky to use both at the same time. I General Question .

  • Suresh Kamath says:

    Do you know of any studies on long term use of clomephene citrate (if used more than 10 years). If one gets occassional blurring of vision how can one know if it is caused by age or sideeffects of Clomephene citerate?

    • maledoc says:

      For the first, unfortunately, no. For the second, that man–as anyone experiencing any side effects with any medication–needs to see a doctor.

  • Jessica says:

    I keep reading how important it is to be monitored by a doctor while taking Clomid. Besides making sure T is going up, what other issues are doctors looking for? What would be possible negative effects?

    • maledoc says:

      You’ll want to read my other posts on this blog: they talk about side effects and how testosterone is turned into estradiol, all of which should be monitored by a physician. All men are different, and different people may experience unusual side effects.

  • Carlos says:

    Hi I heard that estrogen increases body fat in men and that excess body fat increases estrogen levels. If that’s true can you reduce the bodys total estrogen level through excersize to decrease fat?

    • maledoc says:

      That’s not quite right. Fat cells turn testosterone into estrogen, but they also apparently decrease the amount of sex hormone binding globulin, increasing the bioavailable testosterone. The effect is different for every man, and each man should have his own hormones tested to determine his individual physiology.

  • Henry says:

    Let’s say that someone decides that they don’t want to have anymore children and that fertility is no longer an issue. Is testosterone replacement therapy a better option long term compared to clomid?

    • maledoc says:

      Exogenous testosterone is FDA approved for long term use. “Better” is a decision made between a man and his doctor.

  • Henry says:

    Do you know if one has more side effects than the other?

  • Rachel says:

    Dr., Have you ever experienced or seen a male with a normal testoserone level who was taking clomid (to help increase a low sperm count) have a sperm count and mobility go from marginal to very low with no mobility or vitality (life)?

    • maledoc says:

      I’ve seen all sorts of things, Rachel. It sounds like you’re talking about a particular man, and I’d really recommend him talking to his doctor about his particular condition.

  • James Shepperd says:

    This is great thank you.

    Please do one for Anastrozole some day soon..!

  • Shoaib Khan says:

    I am facing the problem of …

    • maledoc says:

      Shoaib, I’m removing the detailed information about yourself that you posted because I respect your privacy. I can’t answer personal questions about your own health. Please read the FAQ.

  • BH says:

    Let’s say that an individual took a cycle of steroids – from reading about clomid, it seems as though this would be an excellent post cycle medication to help with bringing the test levels back up. Would this be a safe assumption?

    • maledoc says:

      I would not encourage a man to think of clomiphene as an intended rescue from loss of sperm production due to external testosterone or testosterone-like drugs. You can’t predict how long or how far sperm production will be decreased by these drugs, and you can’t be sure that clomiphene will be able to rescue sperm production.

      • BH says:

        If you click on this link, I think you will see that clomiphene is one of the best post cycle therapies (link removed) I enjoy reading your posts, but sometimes, personal opinions can get in the way of what people are actually using these drugs for. I would encourage you to revisit your thoughts on the effects of clomiphene for a post-cycle treatment. It is a highly sought after treatment. Although, it always recommended that you get the correct dosage amounts prescribed by your physician.

        • maledoc says:

          Hi John, you’re right, I have opinions, based on experience and scientific studies. I’ve removed the link, as I can’t link from this blog to places that I really don’t think are safe for men. I respect your opinion, and hope that you respect mine.

  • Johan says:


    I have not seen this yet: How long does clomid take to start increasing testosterone/sperm count in the testes?

    Are you aware of any increased risk of health problems in males who use clomid?

    • maledoc says:

      Hi John, please read my other posts and comments on this blog. More than just this one post discusses clomiphene treatment for a man.

  • Mohan says:

    Hi Doctor,

    I am 25 and have…

    • maledoc says:

      Hi Mohan, I’ve edited your comment for your privacy. I’m sorry, but I can’t answer personal questions about your own health. Please read the FAQ.