The relationship between oxytocin and human sexual response is unclear. At least two non-controlled studies have found increases in plasma oxytocin at orgasm in both men and women.[5][6] The authors of one of these studies speculated that oxytocin's effects on muscle contractibility may facilitate sperm and egg transport.[5] Murphy et al. (1987), studying men, found that oxytocin levels were raised throughout sexual arousal and there was no acute increase at orgasm. [7] A more recent study of men found an increase in plasma oxytocin immediantly after orgasm, but only in a portion of their sample that did not reach statistical significance. The authors noted that these changes "may simply reflect contractile properties on reproductive tissue."[8]

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]


If the two things you can't live without are a dark, even tan and a fast-acting, long-lasting erection, then add Melanotan II to your holiday shopping list. This synthetic peptide hormone, which was developed by a research team at the University of Arizona during the late 1990s, darkens skin pigment and may stimulate erectile activity. And despite continued concern and controversy within the medical community regarding its use, it remains available for sale over the internet in a powdered form that can then be reconstituted for subcutaneous injections.
5-HTP increases a brain chemical called serotonin. Taking 5-HTP along with other herbs and supplements that increase serotonin might lead to too much serotonin and cause side effects including heart problems, shivering and anxiety. Other herbs and supplements that increase serotonin levels include Hawaiian baby woodrose, L-tryptophan, S-adenosylmethionine (SAMe), and St. John's wort.
5-HTP is decarboxylated to serotonin (5-hydroxytryptamine or 5-HT) by the enzyme aromatic-L-amino-acid decarboxylase with the help of vitamin B6.[40] This reaction occurs both in nervous tissue and in the liver.[41] 5-HTP crosses the blood–brain barrier,[42] while 5-HT does not. Excess 5-HTP, especially when administered with vitamin B6, is thought to be metabolized and excreted.[43][44]
First, dietary supplements are not regulated as drugs in the US, and the careful testing and quality control that are required of prescription drugs do not apply to supplements like 5-HTP. This is why serious adverse effects and major outbreaks, like the one associated with tryptophan, can occur. You can minimize this risk by using only USP-Verified supplements.
“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.
Jump up ^ Gauquelin G, Geelen G, Louis F, Allevard AM, Meunier C, Cuisinaud G, Benjanet S, Seidah NG, Chretien M, Legros JJ (1983). "Presence of vasopressin, oxytocin and neurophysin in the retina of mammals, effect of light and darkness, comparison with the neuropeptide content of the neurohypophysis and the pineal gland". Peptides. 4 (4): 509–15. doi:10.1016/0196-9781(83)90056-6. PMID 6647119.

Researchers often investigate the effects of hormones on behavior in laboratory experiments with student subjects. Some studies show that when you give people oxytocin they become more generous and trusting. In others that administer testosterone to men, the opposite happens. The strength of such studies is that they can demonstrate cause and effect – the behavior change only occurs in subjects receiving hormones, not in those who get a placebo. But this research has weaknesses as well: it often focuses on single hormones, ignoring their potential interactions, and behavior is measured with highly artificial tasks.
In addition, in the Phase 1 clinical trial in healthy volunteers using a randomised, double-blind, placebo-controlled single- and multiple-dose Phase 1 clinical trial, the safety and pharmacokinetics of the intravenous administration of TB-4 was evaluated. From this, intravenous administration of TB-4 appears to be safe and well-tolerated by all subjects with no dose limiting toxicity or serious adverse events reported.
It has been shown that oxytocin differentially affects males and females. Females who are administered oxytocin are overall faster in responding to socially relevant stimuli than males who received oxytocin.[75][86] Additionally, after the administration of oxytocin, females show increased amygdala activity in response to threatening scenes; however, males do not show increased amygdala activation. This phenomenon can be explained by looking at the role of gonadal hormones, specifically estrogen, which modulate the enhanced threat processing seen in females. Estrogen has been shown to stimulate the release of oxytocin from the hypothalamus and promote receptor binding in the amygdala.[86]

5-HTP has been linked in very rare instances to a condition known as EMS, or eosinophilia-myalgia syndrome, which combines extreme muscle tenderness with abnormalities in the blood. A contaminant that was found in some tryptophan supplements in the late 1980s, and was linked to a small number of EMS cases, was also found in some 5-HTP supplements.  It’s important to talk with your doctor before you begin taking 5-HTP or any other supplement, and to make sure you’re getting your supplements from a reliable provider.  
Supplements haven't been tested for safety and due to the fact that dietary supplements are largely unregulated, the content of some products may differ from what is specified on the product label. Also keep in mind that the safety of supplements in pregnant women, nursing mothers, children, and those with medical conditions or who are taking medications has not been established. You can get tips on using supplements, but if you're considering the use of 5-HTP supplements, talk with your primary care provider first. Self-treating a condition and avoiding or delaying standard care may have serious consequences.

Evidence accumulated over the past decades has overturned the traditional dogma that the adult mammalian brain cannot generate new neurons. Adult neurogenesis has been identified in all vertebrate species examined thus far including humans.44-49 Newly generated neuronal cells originate from neural stem cells in the adult brain. Neural stem cells are the self-renewing, multipotent cells that generate the neuronal and glial cells of the nervous system.50 The major function of neurogenesis in adult brain seems to replace the neurons that die regularly in certain brain areas. Granule neurons in the DG continuously die and the progenitors in the subgranular zone of the DG may proliferate at the same rate as mature neuronal death to maintain a constant DG cell number.51 Similarly, the newly proliferated cells from the subventricular zone migrate and replenish the dead olfactory bulb neurons.52 Here, we focus on DG neurogenesis which is important for spatial learning and memory. In normal adult rats, newborn neural cells migrate from the subgranular zone of the DG of the hippocampus into the granule cell layer and eventually become mature granule neurons.53 These new granule neurons extend axonal processes to their postsynaptic targets54-57 and receive synaptic input.58 TBI stimulates widespread cellular proliferation in rats and results in focal neurogenesis in the DG of the hippocampus.59,60 Some of the newly generated granule neurons integrate into the hippocampus. The integration of the injury-induced neurogenic population into the existing hippocampal circuitry coincides with the time point when cognitive recovery is observed in injured animals.44
Recent reports have stated that inhibitors of Wnt signaling have emerged as promising strategies for bone disease and inflammatory diseases [26, 55]. Wnt5a, one of the most common Wnt molecules that activate the non-canoical pathway, binds to Fzd and its co-receptor, Ror2 [56]. In synoviocytes from rheumatoid arthritis patients, the expressions of Wnt5a and Frizzled5 (Fzd5) were significantly enhanced [25] and their blockades inhibited synoviocyte activation [55]. Recently, Wnt5a was highly expressed in synovial tissues in a mouse model of rheumatoid arthritis where inhibition of Wnt5a-Ror2 signaling suppressed bone loss [57]. Our data demonstrated that ROS up-regulated Wnt5a and its cell surface receptors, Frizzled and Ror2, as well as mRNA and protein expressions in time- and dose-dependent manners in PDLCs.

The structure of oxytocin is very similar to that of vasopressin (cysteine - tyrosine - phenylalanine - glutamine - asparagine - cysteine - proline - arginine - glycine), also a nonapeptide with a sulfur bridge, whose sequence differs from oxytocin by 2 amino acids. A table showing the sequences of members of the vasopressin/oxytocin superfamily and the species expressing them is present in the vasopressin article. Oxytocin and vasopressin were isolated and synthesized by Vincent du Vigneaud in 1953, work for which he received the Nobel Prize in Chemistry in 1955.
TB-500 was identified as a gene that was up-regulated four-to-six fold during early blood vessel formation and found to promote the growth of new blood cells from the existing vessels. This peptide is present in wound fluid and when administered subcutaneously, it promotes wound healing, muscle building and speeds up recovery time of muscles fibres and their cells. An additional key factor of TB-500 is that it promotes cell migration through a specific interaction with actin in the cell cytoskeleton. It has been demonstrated that a central small amino acid long-actin binding domain has both blood cell reproduction and wound healing characteristics. These characteristics are uncovered by accelerating the migration of endothelial cells and keratinocytes. It also increases the production of extracellular matrix-degrading enzymes.
5-HTP is very reliable in increasing serotonin levels. 5-HTP is actually used as a clinical test to judge the potency of drugs that affect serotonin levels (by pairing an experimental drug with 5-HTP to induce 'serotonin syndrome', or serotonin toxicity, one can see how much that drug exacerbates serotonin biosynthesis or bioavailability by seeing how much of a 5-HTP dose is required to induce the syndrome; the lower dose indicative of higher drug potency). This test is known as the 5-HTP induced syndrome test.[8]
Jump up ^ Wei D, Lee D, Cox CD, Karsten CA, Peñagarikano O, Geschwind DH, Gall CM, Piomelli D (November 2015). "Endocannabinoid signaling mediates oxytocin-driven social reward". Proceedings of the National Academy of Sciences of the United States of America. 112 (45): 14084–9. Bibcode:2015PNAS..11214084W. doi:10.1073/pnas.1509795112. PMC 4653148. PMID 26504214.

Addiction vulnerability: Concentrations of endogenous oxytocin can impact the effects of various drugs and one's susceptibility to substance use disorders. Additionally, bilateral interactions with numerous systems, including the dopamine system, Hypothalamic–pituitary–adrenal axis and immune system, can impact development of dependence. The status of the endogenous oxytocin system might enhance or reduce susceptibility to addiction through its interaction with these systems. Individual differences in the endogenous oxytocin system based on genetic predisposition, gender and environmental influences, may therefore affect addiction vulnerability.[72] Oxytocin may be related to the place conditioning behaviors observed in habitual drug abusers.
The scientists discovered that oxytocin strengthens negative social memory and future anxiety by triggering an important signaling molecule -- ERK (extracellular signal regulated kinases) -- that becomes activated for six hours after a negative social experience. ERK causes enhanced fear, Radulovic believes, by stimulating the brain's fear pathways, many of which pass through the lateral septum. The region is involved in emotional and stress responses.
The oxytocin peptide is synthesized as an inactive precursor protein from the OXT gene.[18][19][20] This precursor protein also includes the oxytocin carrier protein neurophysin I.[21] The inactive precursor protein is progressively hydrolyzed into smaller fragments (one of which is neurophysin I) via a series of enzymes. The last hydrolysis that releases the active oxytocin nonapeptide is catalyzed by peptidylglycine alpha-amidating monooxygenase (PAM).[22]
Ingroup bonding: Oxytocin can increase positive attitudes, such as bonding, toward individuals with similar characteristics, who then become classified as "in-group" members, whereas individuals who are dissimilar become classified as "out-group" members. Race can be used as an example of in-group and out-group tendencies because society often categorizes individuals into groups based on race (Caucasian, African American, Latino, etc.). One study that examined race and empathy found that participants receiving nasally administered oxytocin had stronger reactions to pictures of in-group members making pained faces than to pictures of out-group members with the same expression.[62] This shows that oxytocin may be implicated in our ability to empathize with individuals of different races and could potentially translate into willingness to help individuals in pain or stressful situations. Moreover, individuals of one race may be more inclined to help individuals of the same race than individuals of another race when they are experiencing pain. Oxytocin has also been implicated in lying when lying would prove beneficial to other in-group members. In a study where such a relationship was examined, it was found that when individuals were administered oxytocin, rates of dishonesty in the participants' responses increased for their in-group members when a beneficial outcome for their group was expected.[63] Both of these examples show the tendency of individuals to act in ways that benefit those considered to be members of their social group, or in-group.
It’s a compound that the body needs in order to make serotonin, which is our main “happiness hormone.” Per Dr. Oz, 5-HTP floods the brain with serotonin and helps minimize stress, sadness, anger, and anxiety. “5-HTP targets specific emotions that drive us to overeat,” Dr. Bhatia explains. And as she already mentioned, 5-HTP also reduces physical hunger pangs and emotional cravings. Ideally, the body makes its own 5-HTP from the amino acid tryptophan, found in foods like turkey and bananas. (Why not just eat more turkey or take a tryptophan supplement? If you struggle with mood or weight, it can be a sign that your body has trouble converting tryptophan to 5-HTP.) Besides making it yourself, the only other way to get 5-HTP is from a supplement. One we like is the BRI 5-HTP Supplement ($16 for 120 capules, Amazon).
Doctors have noticed cancer patients have a higher amount of Thymosin in the affected tissues than other people. So in the early stages of research, doctors assumed that this meant Thymosin may cause cancer. After more research was conducted, it was discovered that the main action of Thymosin Beta 4 was to produce new white blood cells – so its presence in the body in the areas affected by cancer was likely not a cause of the cancer, but instead, a matter of “showing up” in the body where cancer lived to help the body mount an immune system response.
I bought 200mg "double strength" tablets off Amazon. Immediately after taking them, I felt slightly better. After a week of taking one of these with my breakfast, I could easily get through a working day without being too panicked to concentrate on a screen. I still woke up with 'the fear' but it was lessened. Better yet, there seemed to be no notable side effects. I started recommending it to all my friends with mild depression or anxiety. I was in love.
Down syndrome. Some research shows that giving 5-HTP to infants with Down syndrome might improve muscle and activity. Other research shows that it does not improve muscle or development when taken from infancy until 3-4 years of age. Research also shows that taking 5-HTP along with conventional prescription drugs does improve development, social skills, or language skills.
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