Thymus Rejuvenation

to start with digging in scientific background information, please take a look at:

http://www.anti-agin...une-senescence/

isn't there a compound called thymosin that works on the thymus that seem to have gotten lost and forgotten due to FDA regulations etc. 

But I think this product here is the same product as thymosin only called thymucin:

https://www.pureform...erapeutics.html

I would appreciate if someone here could explain what the importance of the thymus is, I'm a bit clueless about it due to its obscurity. I think thymosin was considered an immune system "stimulant". I'll find the source of where I read about it once I have time. Chime in everyone...

It's really not clear that oral arginine substantially increases growth hormone secretion, particularly in physically active people or in combination with exercise:
 

The Ergogenic Potential of Arginine
It is well documented that the infusion of arginine stimulated growth hormone secretion from the anterior pituitary [5, 7]. This increase in growth hormone secretion from arginine infusion has been attributed to the suppression of endogenous somatostatin secretion [8]. The amounts of arginine infused to elicit the growth hormone response ranged from 12 grams to 30 grams. The clinical investigations of oral consumption of arginine and its impact on growth hormone release are not in agreement. When arginine (1.2 g) was ingested along with the amino acid lysine (1.2 g) in young males, peak plasma growth hormone concentrations increased 8-fold at 90 minutes post-ingestion [9]. However, when arginine and lysine were ingested alone at the same doses, there was no corresponding increase in plasma growth hormone. Suminiski and associates [10] reported that the ingestion of arginine (1.5 g) and lysine (1.5 g) resulted in a 2.7-fold increase in plasma growth hormone concentrations in resistance trained males. Colombani et al. [11] supplemented marathon runners with 15 g arginine aspartate for 14 days before a marathon run. On the day of the marathon, blood samples were taken shortly before the run, after 31 km, at the end of the run, and after a recovery period of two hours. The researchers found that growth hormone concentrations were elevated during a marathon run to a greater degree than exercise would elicit alone.
 
Other studies using either resistance trained or physically active individuals showed no increases in plasma growth hormone concentrations following arginine supplementation. When resistance trained males consumed approximately 8 grams of arginine daily for 17 days there was no associated changes in growth hormone concentrations [12]. Similarly, Lambert et al. [13] gave male bodybuilders 1.2 g of arginine and 1.2 g of lysine. This supplementation did not induce a statistically significant increase in serum growth hormone concentrations over a 3 hour period. In a recent review, Chromiak and Antonio [4] highlighted several factors that appear to modify the growth hormone response to amino acid administration. These include training status, age, sex, diet, and time since last meal. Also, the growth hormone response to amino acid ingestion may be reduced in exercise-trained individuals [4]. These authors concluded that the practice of consuming specific amino acids, including arginine, during or after exercise does not appear to be effective [4].

Growth hormone, arginine and exercise
Recent studies have shown that resting growth hormone responses increase with oral ingestion of L-arginine and the dose range is 5–9 g of arginine. Within this range there is a dose-dependent increase and higher doses are not well tolerated. Most studies using oral arginine have shown that arginine alone increases the resting growth hormone levels at least 100%, while exercise can increase growth hormone levels by 300–500%. The combination of oral arginine plus exercise attenuates the growth hormone response, however, and only increases growth hormone levels by around 200% compared to resting levels.
Summary: Exercise is a very potent stimulator of growth hormone release and there is considerable research documenting the dramatic growth hormone rise. At rest oral L-arginine ingestion will enhance the growth hormone response and the combination of arginine plus exercise increases growth hormone, but this increase may be less than seen with exercise alone. This diminished response is seen in both in both younger and older individuals.

 
Additionally, although it's been tested in unhealthy people, trials of chronic arginine supplementation in patients with diabetes or various forms of CVD have shown no benefit, and tended to suggest harm (1-5).
 
References
1: Tsai CH, Pan TL, Lee YS, Tai YK, Liu TZ. Evidence that high-dose L-arginine may be inappropriate for use by diabetic patients as a prophylactic blocker of methylglyoxal glycation. J Biomed Sci. 2004 Sep-Oct;11(5):692-6. PubMed PMID: 15316145.

2: Loscalzo J. Homocysteine trials--clear outcomes for complex reasons. N Engl J Med. 2006 Apr 13;354(15):1629-32. Epub 2006 Mar 12. PubMed PMID: 16531615.

3: Jahangir E, Vita JA, Handy D, Holbrook M, Palmisano J, Beal R, Loscalzo J, Eberhardt RT. The effect of L-arginine and creatine on vascular function and homocysteine metabolism. Vasc Med. 2009 Aug;14(3):239-48. PubMed PMID: 19651674; PubMed Central PMCID: PMC2840406.

4: Cosentino F, Hürlimann D, Delli Gatti C, Chenevard R, Blau N, Alp NJ, Channon KM, Eto M, Lerch P, Enseleit F, Ruschitzka F, Volpe M, Lüscher TF, Noll G. Chronic treatment with tetrahydrobiopterin reverses endothelial dysfunction and oxidative stress in hypercholesterolaemia. Heart. 2008 Apr;94(4):487-92. Epub 2007 Oct 4. PubMed PMID: 17916662.
 
5. Andrew M. Wilson, MBBS, PhD; Randall Harada, MD; Nandini Nair, MD, PhD; Naras Balasubramanian, PhD; John P. Cooke, MD, PhD
L-Arginine Supplementation in Peripheral Arterial Disease: No Benefit and Possible Harm