From what I have seen on the Peak Testosterone Forum, most men starting out on HRT (TRT) want to go as high as their doctor will let them. The reasons are obvious, right? More libido, better erectile function, more muscle obviously?. The answers to these is not at all obvious and the honeymoon stage is often over quickly – within a few weeks or months of strong start with testosterone. I have even seen an interesting countertrend of late: men wanting to go lower with their dosage of testosterone. Below I have put together some interesting cases of men doing just that or of men struggling with what is clearly overly high testosterone dosages for their physiology.
Before you read the cases below, keep in mind that a good percentage – I’d guess a half or two thirds – of men on a well-run protocol experience a net positive benefit from being on testosterone therapy. It may take a few months and some fine tuning, but they get there and are glad overall that they did. And a pretty good percentage of men that have unsuccessful experiences have medical conditions ,such as low SHBG, severe depression and anxiety, obesity, heart disease, etc. The stories below are not meant to scare any one away from HRT but rather point out that reasonable dosing is imperative for some men. Remember: dosage is everything and it’s better to play it safe and start low. You can always boost your testosterone a little later if you need it.
Below are Seven Reasons that Low Dose Testosterone Are Often Better for Many Men. (I don’t mean ridiculously low by the way. When I first went on HRT, my urologist put me on a weak compounded testosterone cream that did not even boost my testosterone over 500 ng/dl. This was of minimal benefit. However, I have found that neither do I need testosterone levels near the top of the range either, i.e. approaching 1200 ng/dl.)
1. Better Morning Erections. There are a few of us on the Peak Testosterone Forum that have noticed that our morning erections were stronger on the last day before our cypionate injections, when testosterone and estradiol were lowest. And we also have noticed that we started our HRT cypionate experience with fairly high dosages initially and probably benefited from the “jumpstart” effect. However, as time went on, we felt worse on the high dosages and had to slowly taper off. (You can read the commentary in this thread if you are interested.) For example, I have been doing very well on a 40 mg every 3.5 day protocol, i.e. about 80 mg/week. This is about half the dose that my initial HRT clinic put me on!
And notice the irony: his doctor gave him more testosterone to feel better, but it actually produced the opposite response. No, more is not always better.
3. Sexual Dysfunction. This is a story about a man put on Nebido and, unfortunately, once you are injected with it, there is no going back. It is based on the long-lasting testosterone ester undecanoate and injection frequency varies widely between 8 and 12 weeks generally. Therefore, one injection will affect you for months afterward and this man started off with nightmare experience:
“Hi, been on nebido for 10 months and it doesnt work, its not that i dont feel any effect it actually makes me worse the higher T gets. When I take an injection its very quickly complete loss of erection, lower libido, fatigue, harder to sleep, less energy and lots more. The first 4 weeks is the worst then it slowly starts going back, after 12 weeks when T is down to 8-9 most of the problems from the injection have disappeared and now I get an injection every 8 week so its anything but pleasant, with injection every 8 week my T level is 19 right before next injection, range for testosterone is 10-30.” 
Some of you more savvy readers will note that in the case of #1 and #2, there was either inadequate estradiol management or none. That is true, but I would point out that men often feel worse even when Arimidex is used. And Arimidex can effect the clotting cascade as well.
5. Anxiety, Agitation and Nightmares. One man on our forum was put on a high dose of 200 mg of testosterone cypionate every two weeks. Of course, this is an antiquated and outdated protocol, but it underscores what can happen if a man takes too much:
“After the second injection, I felt agitated and anxious later that night. (last Friday).I had a follow up appointment today, and told the Doc that I’ve had anxiety attacks, and surges of energy- completely amped up, vivid nightmares, and completely agitated. He said it was extremely rare, and usually only on extremely high overdoses.” 
A similar story was echoed by one of our senior posters, who said, after being boosted into the mid 900’s, that “this is exactly what I am experimenting for the past 2 weeks or so I switched my injection protocol to be: 60mgT E3d with 250IU HCG, IM. Between 1/9 and 2/3 My T and E came up to 949(tt) 32.5(FreeT) and 29(ultrasensitive E2) I slowly, began waking up with more and more anxiety. Caused by nothing. Yesterday I could barely sit still at work, everything drove me nuts, every email, every person…. I felt so [expletive deleted] anxious.” 
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6. Elevated Blood Pressure and Pulse. This is quite common and, of course, is counterproductive to your long term health. Research has shown that prehypertension is dangerous to your arteries and read this page to see why an elevated heart rate is the same: The Cardiovascular Dangers of an Elevated Pulse Rate. Notice how quickly and powerfully it hit this man: “”On the day 5 after insertion in the evening I suddenly felt an agitated state of mind, and tension. It almost feel like I have intoxication and high blood pressure. I woke up at night with heart palpitations, uneasy feeling in heck/head, and feeling of being depersonalized, as if things were happening not in this reality. I never felt anything like that before. It was scary/horrifying. This night I slept maybe 3 hours total. In the morning I started to feel that it is getting worse. In fact, symptoms resembled heart attack. So I went to GP, she measured blood pressure 122/74, normal. Pulse rate was elevated to about 100. So it appeared to be an anxiety/panic attack.” 
7. High Hematocrit. If you go too high with testosterone, you can end up with hematocrit, hemoglobin and/or RBC counts. This is because testosterone is involved in red blood cell production and so, if you go too high with your testosterone dosage, you can put your body into overdrive. This can have very serious side effects that we have seen from time to time on the forum, including shortness of breath, facial flushing, high blood pressure, etc. Potentially, it is very dangerous, as illustrated in this Story of Abusing Testosterone. Occasionally, a man cannot lower his hematocrit low enough (by donating blood usually) and will have to actually go off of HRT entirely.
SUMMARY: Many men actually do better with their peak testosterone in the mid upper range of testosterone. In some cases, the mid range or even lower mid range may produce better results. Testosterone levels are very individual and no one size fits all. Going for a lower dosage on your testosterone level will generally produce less side effects and decrease your risk of having to actually quit HRT (TRT) altogether.