NOTE: Testosterone enanthate and cypionate share very similar half-lives and dosages. In the U.S. testosterone cypionate is typically used and enanthate rarely. However, in many other countries, the opposite is true. The general comments on this page apply to BOTH enanthate and cypionate.
This is a particularly relevant topic, because an every-two-week protocol is still practiced by most endocrinologists around the globe. In the U.S., things are finally changing, but many countries still have the vast majority of their endos insisting on an injection every two weeks and sometimes even three or four! This leaves many men around the globe in a terrible quandry: should they take a horrible protocol just to get into the system or just stay hypogonadal without treatment? Again, in the case of an every other week protocol, the cure is almost worse than the disease!
And no wonder so many endocrinologists hate HRT: their patients hate their lame protocol. The poor men being treated this way come back to the endo saying, “Well, I felt good for a couple of days but then I was miserable. If fact, I felt worse than before HRT. What’s wrong doc?” And the endocrinologist thinks to himself: “Well, I’ll tell you what is wrong: HRT sucks!”
The reality is that testosterone cypionate injections are used by HRT clinics and many savvy docs with great success, but the secret is predicated on that fact that it needs to be done weekly or even twice per week!
Let’s look at some research that show just how bad cypionate (or enanthate) injections really are if done improperly. One study looked at nine hypogonadal Japanese males with total testosterone < 270 ng/dl or free testosterone < 10 pg/ml.  These are very low testosterone levels and would constitute hypogonadism with almost any lab. The researchers then gave these men a single 125 mg dose of testosterone enathate and monitored their testosterone levels. The results were very revealing:
- Day 0: Total Testosterone ~400 ng/dl
- Day 7: Total Testosterone ~620 ng/dl
- Day 14: Total Testosterone ~200 ng/dl
What this study clearly showed is that testosterone levels are actually raised a little over baseline after a week, which explains why a weekly protocol is so often successful. However, by the two week point, total testosterone actually collapses below these men’s already very low baseline testosterone levels. This is very ugly as HRT done this way actually makes a bad situation worse for probably four or five days!
And, for those poor guys who are put on an every three or four week protocol – well, they likely have extremely low testosterone for weeks! One poor guy wrote in with a horror story about just this situation:
“I am 35 years old. I just started trt. My test levels were 280 ng/dl. Immediately doc put me on 2cc of 400mg of test cypionate once a month. I don’t have blood results. I just know that I really start feeling terrible after about 2 and a half weeks. I know this is vague info. But does this sound normal? Feel so down and out. Any help or opinions will be greatly appreciated.” 
By the way, there is something else horrible about this every four week protocol. Look at the dose this doctor gave him: 2 cc (which is 2 ml). Testosterone cypionate usually comes in 200 mg/cc concentrations and so this man probably got 400 mg of testosterone in one injection, which corresponds with what he wrote above. What this means is that on days 1-4 his testosterone levels went through the roof and were VERY high. The doc did this out of ignorance, because he figured that it would help the cypionate last longer. However, because of its relatively short half-life, the cypionate (or enanthate) is almost all gone at about day 10 no matter how much you give him. (Low SHBG men will clear out testosterone even more quickly.) So that monster injection of cypionate will also send the man’s estradiol sky high which yields a completely different set of problems: low libido, erectile dysfunction, bloating, weight gain, gyno, moodiness, etc.
So pull up the above study and show your doctor just what is going on. And notice that it is in an endocrinology journal, so there is no excuse if he is an endo. (You would think that endocrinologists would know about this, but, sadly, many not do not.)
1) Endocrine J, 2006, 53(3):305-310, “Hormone Profiles after Intrasmuscular Injection of Testosterone Enanthate in Patients with Hypogonadism”, https://www.jstage.jst.go.jp/article/endocrj/53/3/53_3_305/_pdf