I am not a doctor and this is not to be taken, interpreted or construed as medical advice. Please talk with a licensed medical professional about this. These are just my own personal thoughts and not a prescription or a diagnosis or any form of health care whatsoever. In terms of doctors, here are a few directories that may help you find a good functional medicine or naturopathic practitioner in your area:

Dosages for maintenance begin once you have achieved your desired level of tan. It requires considerably less frequent dose than once every day. In spite of the fact that levels are diverse for everybody, all things considered 500mcg each 3 to 4 days or 1mg a week with a little measure of UV exposure will keep your tan maintained. It maintains the colour without further darkening the skin.
Horvath, G. A., Stockler-Ipsiroglu, S. G., Salvarinova-Zivkovic, R., Lillquist, Y. P., Connolly, M., Hyland, K., Blau, N., Rupar, T., and Waters, P. J. Autosomal recessive GTP cyclohydrolase I deficiency without hyperphenylalaninemia: evidence of a phenotypic continuum between dominant and recessive forms. Mol.Genet.Metab 2008;94:127-131. View abstract.

Robert Love, a urologist in Dallas, understands why there is such back-channel demand for a product like Melanotan II. "People sometimes want to handle performance issues on their own, without a physician involved, either because they are embarrassed or because they may be uninsured or lack adequate insurance," he told Motherboard. "Handling things this way is not advisable. We have prescription drugs that address erectile dysfunction issues. And although this isn't my area, there are alternative ways of getting suntans—tanning beds, spray tans—though of course extended outdoor sun exposure should be avoided if possible."
Melanotan 2 works by stimulating the release of the pigment melanin from the skin. Less UV exposure is necessary with Melanotan 2 compared to “normal tanning”, and the tan that occurs with tanning injections is deeper and longer lasting than an individual’s “normal tan”. Melanotan works best (has the most noticeable effects) on people with fair skin tones.

The tb-500 has a systematic effect regardless of where it is injected. Some believe that thymosin beta-4 should be injected as close to the injury as possible however there is no evidence to show this would be superior. It can be injected subcutaneously (stomach fat) or intramuscularly (shoulders, thighs, buttocks). Injections should be given in different sites (rotated) each time. Depending on the spot, you can either feel nothing or you can feel slight pain - you will learn your favorite spots in time.
Jump up ^ Vargas-Pinilla P, Paixão-Côrtes VR, Paré P, Tovo-Rodrigues L, Vieira CM, Xavier A, Comas D, Pissinatti A, Sinigaglia M, Rigo MM, Vieira GF, Lucion AB, Salzano FM, Bortolini MC (January 2015). "Evolutionary pattern in the OXT-OXTR system in primates: coevolution and positive selection footprints". Proceedings of the National Academy of Sciences of the United States of America. 112 (1): 88–93. Bibcode:2015PNAS..112...88V. doi:10.1073/pnas.1419399112. PMC 4291646. PMID 25535371.
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.

Melanotan II is a synthetic analogue of the α-melanocyte stimulating hormone (α-MSH). α-MSH is a melanocortin I receptor agonist which has a role in human pigmentation by stimulating production of eumelanin. Melanotan II was originally developed as a treatment for sexual dysfunction. However, the proposal was abandoned when development of the metabolite bremelanotide was established.
There is no long-term side effects ever reported, but there is post injection effects while using Melanotan 2, typically these effects appear during the first few days of dosing and will become increasingly less obvious as the body adjusts to the peptide. These effects include: hot flush in face, mild nausea, decreased appetite, and increased sex drive. In order to combat nausea, an anti-histamine product can be taken until the body gets used to it. But most common way to deal with this is to take the dose before bed.
Why have zebrafish retained the ability to regenerate? It is thought that the capacity for organ regeneration is an ancestral condition that has occasionally been diminished in the course of vertebrate evolution (Scadding, 1977; Goss, 1992; Wagner and Misof, 1992). Thus, most biologists suspect that the molecular machinery to optimize regeneration is present but poorly-utilized in mammals. By this line of reasoning, zebrafish heart regeneration may represent an optimal utilization of universal cardiac machinery.
The reason for the difference is the density of oxytocin receptors in the brain. Life pair bonders, like prairie voles or, indeed, ourselves, have a high density of receptors in the reward centre of the brain. Non-pair bonders, like meadow voles, certainly enjoy sex, but their lower density of receptors means it doesn't matter so much who the partner is. So it's not the oxytocin itself making sex enjoyable. What it's doing is influencing our mating behaviour.
The first study to show that Tβ4-promoted tissue repair was a dermal study performed in rats (Malinda et al., 1999). It had previously been found to promote angiogenesis and was reported to be high in platelets (Grant et al., 1995; Hannappel & van Kampen, 1987; Malinda, Goldstein, & Kleinman, 1997; Philp, Huff, Gho, Hannappel, & Kleinman, 2003). Since platelets are the first cells to enter a wound, it was clear that Tβ4 should be tested in dermal wounds in an animal model (Malinda et al., 1997, 1999; Philp, Badamchian, et al., 2003). In the first dermal study using 8 mm full-thickness punch wounds in rats, Tβ4 at 5 μg/50 μL of phosphate-buffered saline was found to accelerate wound closure, increase angiogenesis, and accelerate collagen deposition (Malinda et al., 1999). Tβ4 was only applied at the time of injury and at 48 h since after that the crust had formed. Visible macroscopic improvement was seen in the treated group by day 4. The study also found that Tβ4 promoted keratinocyte migration in vitro with activity in the picogram range. The findings were confirmed in various additional animal models (Table 1) and led to the clinical trials for hard to heal wound in patients as detailed in Table 2.
Bonding. In the Prairie Vole, oxytocin released into the brain of the female during sexual activity is important for forming a monogamous pair bond with her sexual partner. Vasopressin appears to have a similar effect in males. In people, plasma concentrations of oxytocin have been reported to be higher amongst people who claim to be falling in love. Oxytocin has a role in social behaviors in many species, and so it seems likely that it has similar roles in humans.6
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]