Cardiac effects: oxytocin and oxytocin receptors are also found in the heart in some rodents, and the hormone may play a role in the embryonal development of the heart by promoting cardiomyocyte differentiation.[50][51] However, the absence of either oxytocin or its receptor in knockout mice has not been reported to produce cardiac insufficiencies.[49]
Advice & Tips: 5-HTP is a serotonin precursor. Serotonin is well-known as a hormone that affects one's mood in a positive way, but it is probably less-well known that it increases intestinal motility. It has worked magic for my symptoms. I am completely regular now, and the majority of my days are good days, whereas before I began taking it the majority of my days were bad days that began with symptoms of constipation and intestinal pain or discomfort. For me, at least, this is not a prescription. I began taking 5-HTP after my fiancee'--who had already been taking it to help her mood and, primarily, her difficulty sleeping through the night--learned it can be helpful when taken for gastrointestinal motility, and I began taking it myself shortly after that (and felt its effects almost immediately). Although not entirely unexpected, my slightly enhanced good moods are a nice side benefit of taking the supplement. I do get some very mild undesirable side effects, especially during mid-day when I take twice my morning and evening dose of 100 mg. Sometimes my face feels hot and flushes fairly noticeably--and this may be intensified with eating--but those symptoms subside within probably 30 minutes or less.
Wonderful column. My expertise is the psychology of risk perception, and I have done some reading on oxytocin and trust (not the kind you want to boost in a bar with Liquid Trust – you can the stuff with pheromones – to boost THAT kind of trust). It turns out there is a high concentration of oxytocin receptors on the amygdala, the area of the brain where fear starts. As oxytocin levels go up, the ability of the amygdala to be warry and more mistrustful goes down. I describe this in Ch. 3 of How Risky Is It, Really? Why Our Fears Don’t Always Match the Facts. A few graphs of which are below. I wonder whether the influence of oxytocin on the amygdala might be connected with the finding of the study you write about.
Maternal behavior: Female rats given oxytocin antagonists after giving birth do not exhibit typical maternal behavior.[59] By contrast, virgin female sheep show maternal behavior toward foreign lambs upon cerebrospinal fluid infusion of oxytocin, which they would not do otherwise.[60] Oxytocin is involved in the initiation of maternal behavior, not its maintenance; for example, it is higher in mothers after they interact with unfamiliar children rather than their own.[61]
Thymosin beta-4 (Tβ4) is a water-soluble, 43-amino acid, and 4.9 kDa protein that was originally isolated from bovine thymus [6]. Since Tβ4 is the major actin-sequestering molecule in eukaryotic cells and is found in all cells [7], Tβ4 has multiple diverse cellular functions, including tissue development, migration, angiogenesis, and wound healing [7]. We previously reported that Tβ4-overexpressing transgenic mice, using a construct on the skin-specific keratin-5 promoter, have abnormal tooth development and enhanced stimulation of hair growth [8]. Moreover, exogenous Tβ4 has anti-inflammatory effects in the bleomycin-induced mouse model of lung fibrosis [9], tooth extraction sockets in rats [10], rat model of myocardial ischemia [11], corneal wound healing [12], wound healing of rat palatal mucosa [13], in vitro model of cultured human gingival fibroblasts [14], and cardiac fibroblasts [15]. However, the effects of Tβ4 over expression or inhibition on differentiation are controversial. Exogenous β4 peptide inhibited osteogenic differentiation but facilitated adipogenic differentiation in human bone marrow-derived-mesenchymal stem cells (MSCs) [16]. In contrast, Tβ4 inhibition by Tβ4 siRNA attenuated odontoblastic differentiation in the odontoblast-like cells, MDPC-23 [17]. Moreover, we recently demonstrated that odontoblastic differentiation was enhanced by activation of Tβ4 by Tβ4 peptide but was decreased by Tβ4 siRNA in human dental pulp cells (HDPCs) [18]. However, the effects of Tβ4 on osteoclastic differentiation have not been reported.

Jump up ^ Grottesi A, Sette M, Palamara T, Rotilio G, Garaci E, Paci M (1998). "The conformation of peptide thymosin alpha 1 in solution and in a membrane-like environment by circular dichroism and NMR spectroscopy. A possible model for its interaction with the lymphocyte membrane". Peptides. 19 (10): 1731–8. doi:10.1016/S0196-9781(98)00132-6. PMID 9880079.
In 19 obese females given either placebo or 8mg/kg (weight not actually given, only BMI between 30-40 for women) daily for 5 weeks without any concurrent dietary recommendations, 5-HTP treatment was associated with a decrease in appetite and food intake (resulting in weight loss) without significantly affecting mood state.[9] This study noted that food intake was reduced from an average of 2,903kcal to 1,819kcal (62% of baseline) while placebo only reduced calories to 80%, and the 0.5kg weight loss in placebo was outperformed by a near 1.5kg loss in 5-HTP. These weight loss effects have been noted with 750mg 5-HTP over 2 weeks in overweight diabetics[10] and over 12 weeks in obese persons given 900mg 5-HTP daily (58% of baseline intake); this latter study had a 6 week trial without a diet (in which significant weight loss was only noted at week 6) followed up by coadministration with a diet where weight loss proceeded to reach an additional 3.3kg over the subsequent 6 weeks;[11] this latter study is duplicated in Medline.[12]
It bears understanding that this type of peptide is not a treatment or cure for anything, nor should it be considered a preventative measure to skin cancer. While this tanning peptide is known to protect the skin through the natural tanning process, it is not in and of itself a foolproof UV shield, however it is an excellent way for those who don't tan otherwise to get rich golden tans without as much exposure to the sun.
One study investigating romantic stress that looked at nondepressed youth who went through a recent breakup and were given 60mg of Griffonica Simplicifonia (12.8mg 5-HTP) twice a day for 6 weeks in an open-label study noted reductions in percieved romantic stress when measured at the 3 week mark with no further improvement at 6 weeks; there was no control nor placebo group in this study.[29]
Ok Ben. Thanks. Started the TB 500 for my elbows. Got the 5mg of TB 500 and reconstituted it with 3 cc/ml. of water (3 syringes full) Just about filled the file. Now based on injecting just under .1 cc/ml or just under 10 (8) units for a dose of around 250. How long did that vial last you? Seems like there is a lot left and the amount injected is small. Is my dose and math right?
In years past, oxytocin had the reputation of being an "uncomplicated" hormone, with only a few well-defined activities related to birth and lactation. As has been the case with so many hormones, further research has demonstrated many subtle but profound influences of this little peptide, particularly in regards to its effects in the brain. Oxytocin has been implicated in setting a number of social behaviors in species ranging from mice to humans. For example, secretion or administration of oxytocin in humans appears to enhance trust and cooperation within socially-close groups, while promoting defensive aggression toward unrelated, competing groups.

The mRNA and protein expressions were determined by PCR analysis (A) and Western blot analysis (B), respectively. The bar graph shows the fold increase in protein or mRNA expression compared with control cells * Statistically significant differences compared with the control, p<0.05. The data presented were representative of three independent experiments.

“The study is kind of a high-water mark for the field, putting different levels all together: a robust behaviour, a brain region, and a cellular basis for it,” says Richard Tsien, a neuroscientist also at Langone. Tsien has been studying the action of oxytocin on neuronal circuits in detail, by examining slices of the hippocampus, a region involved in learning and memory. In a 2013 study6 of rats, Tsien's team found that oxytocin selectively acts on a type of cell called an inhibitory interneuron in a way that quiets background chatter within the neuronal circuit. “Oxytocin improved signal transmission, almost doubling the ability of information to flow through the system,” Tsien says. In effect, it is producing more signal and less noise.
FGF-2 and VEGF enhance angiogenesis in chronic wounds (Greenalgh, 1996; Kirchner et al., 2003). Thymosin β-4 increases angiogenesis, consistent with its ability to induce epicardial cells to differentiate into endothelial and smooth muscle cells of coronary vessels (Chapter 7). L-arginine enhances angiogenesis in chronic wounds by enhancing the production of endothelial nitric oxide and improving blood flow (Shi et al., 2003). L-arginine also plays a role in the formation of proline, which is essential for the structure of collagen molecules. ChrysalinTM, a synthetic peptide representing the portion of human thrombin that binds to the surface of endothelial cells, doubled the incidence of complete healing of diabetic foot ulcers in human patients (Fife et al., 2007). Another molecule used to treat peripheral artery disease, pentoxifylline, was reported to improve blood flow in chronic wounds by reducing blood viscosity (Falanga et al., 1999).
A critical step in wound healing is angiogenesis. New vessels are needed to supply nutrients and oxygen to the cells involved in repair, to remove toxic materials and debris of dead cells and generate optimal conditions for new tissue formation. Another important step is the directional migration of cells into the injured area, joining up to repair the wound. This requires an attractant that will direct the cells to the wound and propel them to the site. These critical steps in wound healing are regulated by beta 4, as seen in the following experiments.

In a study measuring oxytocin serum levels in women before and after sexual stimulation, the author suggests it serves an important role in sexual arousal. This study found genital tract stimulation resulted in increased oxytocin immediately after orgasm.[105] Another study reported increases of oxytocin during sexual arousal could be in response to nipple/areola, genital, and/or genital tract stimulation as confirmed in other mammals.[106] Murphy et al. (1987), studying men, found oxytocin levels were raised throughout sexual arousal with no acute increase at orgasm.[107] A more recent study of men found an increase in plasma oxytocin immediately after orgasm, but only in a portion of their sample that did not reach statistical significance. The authors noted these changes "may simply reflect contractile properties on reproductive tissue".[108]

Other supplements are available which have appetite supressant and mood enhancing effects similar to 5-HTP. These type of ingredients are often included, in optimal pre-formulated dosages in fat burners. Phenylethylamine is also another ingredient with mood enhancing potential that is often found in fat burners in place of 5-HTP. 5-HTP can be found in some sleep supplements, though in Australia they are replaced by ingredients such as GABA and phenibut.
Letdown reflex. In lactating (breastfeeding) mothers, oxytocin acts at the mammary glands, causing milk to be ‘let down’ into a collecting chamber, from where it can be extracted by compressing the areola and sucking at the nipple. Sucking by the infant at the nipple is relayed by spinal nerves to the hypothalamus. The stimulation causes neurons that make oxytocin to fire action potentials in intermittent bursts; these bursts result in the secretion of pulses of oxytocin from the neurosecretory nerve terminals of the pituitary gland.
5-HTP is sometimes taken by people coming down from MDMA to relieve post-MDMA dysphoria.[8] As 5-HTP is a necessary precursor for the brain to produce more serotonin, and MDMA use depletes a person's natural serotonin levels, it is believed that taking 5-HTP after consuming MDMA will speed up serotonin production. DanceSafe claims that the anecdotal evidence is widespread and that the theory is physiologically reasonable.[9] Backing up this approach is research conducted by Wang, et al.  in 2007, which observed that MDMA-induced depletions of 5-HT (serotonin) were restored in rats after administration 5-HTP, and suggested that this approach might be clinically useful in abstinent MDMA users.[8]