Disclaimer: Everything here is opinion only, and was written by a contributing author. This is not medical advise. Please consult with your doctor.
Exogenous vs. Endogenous:
Growth hormone is produced by glands in the brain. Direct injection of growth hormone is known as “exogenous growth hormone injection”. Such injections should only be done in extreme cases, such as when the pituitary and/or hypothalamus has ceased functioning or is absent, because exogenous growth hormone will otherwise cause your body to shut down its natural growth hormone production.
There are peptides that can stimulate the pituitary gland naturally into producing more growth hormone. These peptides are known as Endogenous Growth Hormone Secretagogues.
CJC-1295 / Ipamorelin:
This is probably the most common peptide GH secretagogue. They are usually paired together, as they work synergistically in combination. However, Ipamorelin also stimulates the body into releasing higher Ghrelin levels, and Ghrelin stimulates hunger. This is often good for body builders (it helps them put on muscle), but bad for overweight people (it makes it more difficult to lose weight).
CJC-1295 Research Data:
Ipamorelin Research Data:
Tesamorelin:
Tesamorelin is a GH secretagogue that does not stimulate Ghrelin. It is probably the preferable peptide for overweight people.
Research Data:
Other Peptides:
There are a number of other peptides that are also GH secretagogues, such as GHRP-2, GHRP-6, MK-677, and Sermorelin. I don’t know much about them, and don’t recommend them when there are better known peptides.
Exogenous HGH:
In my battle to save my knees, I had been taking a variety of peptides. Some of those peptides were for increasing my own body’s HGH production, because without adequate growth hormone, your body will not heal. But then after a few months, my physician told me:
“Nevin, I suggest you skip the growth hormone releasing peptides, and just go straight to HGH“
I resisted at first, because I knew that HGH shots would make my body down-regulate its own HGH production. But after studying how to restart my own HGH production, I felt confident that I could easily restart it.
My first HGH injection was 1 IU (International Unit) on 6/28/25, whereupon I gradually increased to 2 IU’s, and then very briefly to 3 IU’s, then back to 2 IU’s. And yes, my own HGH production tanked, because my body saw that I already had enough HGH and saw no reason to produce it. I continued this protocol until 4/4/26 (about 9 months), whereupon I abruptly stopped all HGH shots, and went back to using the growth hormone releasing peptides Tesamorelin, CJC-1295, and Ipamorelin.
On 4/25/26 I tested my IGF-1 levels (growth hormone). My IGF-1 was 116 (reference range is 59-230). Since HGH has a half life of only a few hours, and it had been 3 weeks since my last HGH shot, I knew that the peptides had restored a significant amount of my normal HGH production. And I felt like continuing this “off ramp” protocol would increase it beyond 116.
However, what I want the level to be is “optimal”, not “normal”. Furthermore, I want “optimal” levels for a 35 year old male, which is very difficult to achieve, considering that beginning at about the age of 30, growth hormone levels begin to decline about 15% per decade.
I believe optimal IGF-1 is over 200. A good level is anything over 150. Anything from 100 to 150 is probably OK, but definitely not optimal. And anything under 100 needs help.
Considering my age (68), and my IGF-1 level (116), and the fact that optimal is a number over 200, I made the decision to restart exogenous HGH.
My conclusion: I think it’s pretty easy to restart your HGH production with peptides. My protocol to do so was:
Tesamorelin: 1mg daily
CJC-1295 (no DAC) with Ipamorelin: 200mcg daily
CJC-1295 / Ipamorelin usually comes blended in the same vial, with equal amounts of each in the vial.
Your body’s normal growth hormone releases typically come in pulses at night, so take at least one of those peptides just before bed.
Eating makes your body release insulin, and insulin competes with growth hormone, so have at least a 1 hour “no eating” window on either side of taking these peptides, or it will reduce the effectiveness of the peptide.
Also, I would space the peptide shots by at least one hour between them. You might try, for example, CJC/Ipa fasted in the morning, then waiting an hour for breakfast, then taking Tesamorelin just before bed, but after at least an hour after eating (many other schedules are possible and can be effective– this is just one example of many).