[Dynseli]

The breast is largely composed of glandular (apocrine) tissue surrounded by adipose tissue. This glandular tissue is made up of numerous milk producing lobules.
The endocrine system, including the pituitary gland, regulates mammary glands. Areolar and mammary glands are exocrine glands.

Mammary gland cells contain 'estrogen receptor alpha' (ER-α), 'progesterone receptor' (PR), and 'prolactin receptor' (PrLR) proteins.
Estradiol, progesterone and prolactin normally activate the respective receptors that cause breast growth. Estrogens, and progestogens are different categories of sex hormones. Prolactin is another type of hormone that reduces estrogen.

Activation of ER-α causes elongation or horizontal growth of mammary duct cells. PR, believed to be specific to 'Progesterone Receptor B' (PRB), activation causes side-branching of mammary gland cells. Density, Areolar gland development, and gland lactation development are caused by prolactin receptor activation.

Most breast development occurs during the luteal phase, usually days 14 to 28, which is associated with high levels of progesterone and a lesser but significant amount of estrogen. The luteal phase is signaled to start by luteinizing hormone (LH).

During the follicular phase, days 1 through 14, IGF-1 and prolactin are positively correlated with breast size. 'Insulin-like growth factor 1' (IGF-1) causes breast epithelial cell proliferation, and it may allow for breast size maintenance, and growth. Some hormones may be necessary for keeping gains made during the luteal phase.

Estrogen is normally high during ovulation (between menstruation and the luteal phase) and causes breast growth. Breast swelling during luteal phase is also growth, and perhaps antagonists undo this action that is associated with water weight. Progestins may possibly be ER-α antagonists, and estrogens might be PRB antagonists. Certain receptor antagonisms might be necessary to lessen desensitization, due to up or down regulation. However, an overload of antagonisms may damage receptors, desensitizing them.

References
* gland activation - Hormone Action in the Mammary Gland http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2982168/
* mod - Botanical modulation of menopausal symptoms: Mechanisms of action? http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3800090/
* endogenus - Breast Size in Relation to Endogenous Hormone Levels, Body Constitution, and Oral Contraceptive Use in Healthy Nulligravid Women Aged 19-25 Years http://aje.oxfordjournals.org/content/145/7/571.long
* mlpswelling - Breast: premenstrual tenderness and swelling http://www.nlm.nih.gov/medlineplus/ency/...003153.htm

[Dynseli]

Lower androgen levels are correlated with larger breast sizes, especially during the luteal phase, as androgens block estrogen receptors.

LH raises testosterone levels, and LH is also correlated with high estrogen levels. Small amounts of androgens are necessary for normal function. Testosterone can be converted into estrogen via aromatase or DHT via 5-alpha-reducatase enzymes. Excessive DHT causes unwanted effects, while testosterone has minimal unwanted effects.

[Dynseli]

Blocking DHT http://www.breastnexus.com/showthread.php?tid=20884
FAQ-Aromatase for NBE http://www.breastnexus.com/showthread.php?tid=19581
Anti-androgens http://www.breastnexus.com/showthread.php?tid=17416
Testosterone 101 http://www.breastnexus.com/showthread.php?tid=20002

[Tanya Marie Squirrel]

breast structure illustration;

[lareinee]

Thank you @lovely11 for compiling the info with all the links. I feel that this would be useful in the newbie section as well.

Do you have a link for a list of IGF? OR could you recommend a short list please?

What my amateur research on Google can contribute:

"Which foods increase IGF-1 levels?

A number of researchers investigated which foods or nutrients increase levels of IGF-1 in humans. Once again, divergent findings were obtained.

The following foods/nutrients increased IGF-1 levels in humans:

protein derived from milk, fish and poultry, but not red meat (Giovannucci and coworkers, 2003)
protein derived from red meat, fish, seafood and zinc (Larsson and coworkers, 2005)
dietary fat, saturated fat and protein, but not carbohydrate (Heald and coworkers, 2003)
milk, dairy products, calcium, carbohydrate and polyunsaturated fat (Gunnell and coworkers, 2003)
human breast milk (Buyukkayhan and coworkers, 2003)
It is evident that many foods and nutrients raise human IGF-1 levels. What this means in terms of human health and disease is not clear yet, and a great deal of additional research needs to be done to give us definitive answers."

http://www.health24.com/Diet-and-nutriti...1-20120721

I wonder if there is a shortcut, by eating nutrient-rich foods like Spirulina, or placentas, GABA? etc?

[Dynseli]

You're welcome.

Vitamin C raises IGF-1.
Hops also does it.

Healthy fats raise insulin, which is good too. (I'm not sure of the exact relationship between IGF-1 and insulin, but I believe insulin is good for this)
Healthy fats= avocados, natural peanut butter, seeds, nuts, etc

I would imagine other vitamins and nutrients would help. Zinc helps with body repair.

[Candace]

Amino acids at bedtime increase growth hormone release, which elevates IGF-1. Some reasonable doses are 13 g glycine, 1.5 g ornithine, 2 g glutamine, and/or 1 g agmatine. Others can go higher on the ornithine, but I find that too much makes me feel uneasy. Info on agmatine is pretty sketchy, but arginine tastes so bad that I want to believe that agmatine can substitute.

[Missed Miss]

They grow during the luteal phase. What about those who don't ever have a luteal phase?

[Dynseli]

@Candace
Foods high in protein contain many amino acids. If you want to supplement with amino acids, just use a scoop amount of protein powder mixed with Raw sugar (not refined sugar). Avocados, natural peanut butter, seeds, nuts have healthy fats and protein

@Missed Miss
Create or find a way to cycle it. Look at the texts listed under "references," and an encyclopedia. 'mod' is where I got the idea of how to cycle it. What's important, is to understand which hormones are high to create gains. It may not be necessary to cycle it, except to benefit from levels of hormones during different times, and to lower desensitization. One thing that is constant is that prolactin levels are high during sleep. You can focus on aromatase, lowering dht, adjusting progestogens, and adjusting prolactin.

@Tanya Marie Squirrel
Thanks for the illustration. That's the same one from Wikimedia Commons.

[Candace]

To release growth hormone, the amino acids must be free-form. Protein in food is absorbed as peptides so it does not work for this purpose. (Peptides do absorb better than aminos, so food is preferred for general protein requirements.)

Mixing with sugar is going to trigger insulin which will divert the amino acids to protein synthesis instead of the desired pharmacological result. That's why aminos are taken on an empty stomach. (And for growth hormone purposes, bedtime gives the best results because most growth hormone is released at night.)

Is there any evidence that raw sugar is beneficial? I know that honey is, but the sugar is probably just a bystander.

Peanut butter is going to be contaminated to some extent with aflatoxin, a fungal toxin which causes liver cancer. The USA has a rather relaxed standard (20 ppb) while Europe uses 4 ppb. This paper states that "If the level of protection desired is that aflatoxin exposures would not increase lifetime HCC risk by more than 1 in 100,000 cases in the population, then most current regulatory standards are not adequately protective even if enforced". Here's an example of a peanut plant that got away with being filthy for years due to lax oversight.