Tesa (Egrifta) is extremely effective.
It has a much greater safety profile than HGH. It binds to growth hormone stimulating receptors signaling your pituitary to release naturally produced growth hormone.
Once those receptors are saturated, a higher dose of Tesa won't do anything else.
The binding is very long lived, inducing increased growth hormone production for 3 weeks after administration. GH release continues to follow natural fluctuation cycles, but at higher levels.
So with continuous administration, you "max out" natural growth hormone levels, without the supra-physiological spikes caused by HGH use.
Since growth hormone can accelerate undetected cancers, Tesa's limitation to physiological levels and its maintenance of natural growth hormone release cycles, makes growth hormone induced problems less likely while getting the most "natty" growth hormone benefit possible.
Its primary downside is cost.