The potential benefits of HGH use are well documented and I like the idea of using a supplement that allows our body to 'naturally' increase it's production while not abusing it.
To the question of whether or not one should use it during a cycle or during PCT, I would say one would be better served using it on cycle, and for a few reasons. First, cycles are generally longer in duration (6-12 weeks on average) than a typical 4 week PCT. To see positive benefits from increased HGH production (other then improved sleep), HGH or HGH-promoting compounds should be used for longer periods of time then most people will use them. Most guys like to use a bottle or two of a particular substance and then move on to the next newest thing. Second, HGH really does shine when combined with high levels of other anabolic compounds. It has long been considered as the holy grail in the bodybuilding world when you can combine gear with HGH. Lastly, most guys tend to train much harder on cycle and are at an increased risk for injuries and will greatly benefit from the increased reparitive properties of higher than norml levels of HGH/IGF-1 while on cycle.
Having said that, I think using compounds like MK-677 during PCT has its benefits as well. I just think a lot of PCT users will expect some type of miracle during their 30 capsule run of MK-677 during PCT. As far as increasing HGH/IGF-1 during PCT, that can also be done with whey protein/dairy/amino acids, short-burst high intensity training, formestane, and even creatine. There is no doubt though that increased IGF-1 (HGH) during PCT will help with muscle retention after your cycle, as well as healing/regenerating damaged tissues.
The best of both worlds would be to run a compound like MK-677 during the cycle as well as during the post cycle period. On cycle for increased synergism, growth and repair when stacked with other anabolics; During PCT for muscle retention and overall recovery.
It's pretty amazing what HGH/IGF-1 can do within the body. The amount or growth and regeneration it can stimulate is quite impressive, especially when levels are artifically inflated for longer duations of time. Of course, with all that good, there must be some bad too, right? There have been studies that show all that increased growth can lead to increased stress on the body over long periods of time. There have also been non-human studies that show elevated levels of IGF-1 will equate to a shortened lifespan. Also, the ability for IGF-1 to affect cell apoptosis means it may also keep the body from ridding itself of pre-cancerous cells prior to them becoming cancerous. You didn't think all that growth was free did you?
Some of us here are familiar with the knowledge that extreme things lead to extreme outcomes, and the outcomes are not always as we desire. You are told to live an active, healthy lifestyle and not to abuse your body. As bodybuilders, we do things like train beyond where we 'should' with the ultimate goal of being bigger, better, faster and stronger. The exercise can be great for us but excessive amounts of it can also be a degenerative factor on our joints and even our endocrine sytem when 'supplementation' is factored in.
Eating healthy food is great for us but as bodybuilders we take that to the extreme. We slam our faces full of food with the hope of getting bigger, better, faster and stronger. Once again, it had been shown that eating copious amounts of food can lead to more oxidative stress on our bodies and can prematurely age our organs that have to deal with all of the excess. People who eat in moderation are generally better off then bodybuilders that are constantly trying to slam 5000 kcal into their bodies everyday. Let's not even begin with the extreme of heavy bulking and cutting that professional body builders do year 'round. That is a lot of stress on the body. Again, there is always a trade-off.
In my humble opinion, It's no different with artificially raising IGF-1/HGH levels for VERY long periods of time. We are doing something that is naturally out of the normal range of what our bodies would normally do (abnormal HGH deficiencies not withstanding). As we age, our bodies naurally decrease HGH production and I believe that is for a reason and that the reason is natural to the human species. As our cells age and our DNA begins to break down, cell apoptosis needs to take place at an increased rate (not a decreased rate from increased IGF-1) in order for our bodies to stay as healthy as possible for as long as possible. Without the ability for our bodies to kill off damaged cells, we would all have a very poor life that I do not think would last very long. This above consideration is another reason why taking anti-oxidants and catechins such as resveratrol and green tea extract (EGCG) is also a good idea when using substances that can affect cell apoptosis. The anti-oxidants and anti-oxidant promoting compounds (such as EGCG) can help to protect DNA from degredation when the cellular structure has been allowed to live beyond its regular programmed life cycle.
Now, don't think I am bashing the use of HGH, I am not. I am taking MK-677 as we speak and while not all positve, I can see some benefits and am willing to continue with it's use for a decent period of time. My aim will be to see what type of cellular repair I can do while keeping an eye on how my body is changing as well. I think the best use of an HGH secretagogue is to use it for a long enough duration of time to see benefits while not trying to be so greedy as to push the envelope beyond what our bodies can handle. For every positive aspect of increased HGH production there has to be some sort of coinciding action that we may not see as beneficial to the human body. I think there is so much to the natural homesostasis of the human body that is and will forever be very far beyond the grasp of our humanity. Some of the complexities of the human body may be a secret for a reason afterall; self-preservation anybody? Human nature will keep pushing that envelope though, and I have no problem with that. It is what makes us human and all that I have written should just be a consideration, no more no less, of our individual humanity and how we choose to go about exploring that individuality.
Now, bring on dem gains bruh! (with an open mind of course)