Where does the esoteric practice of seminal retention come from?
Its origins can be traced back as far as 8,000 years ago in ancient China, says Taoist Master Mantak Chia. Its origins pre-date Taoism by a long shot (c. 500 BCE). But the Taoist Masters were the ones who sought to preserve the teachings and shepherd the sacred sexual practice of Sexual Kung Fu into the 21st Century. The teachings still exist today, and make up a large part of what is often mistakenly labelled as "tantra" in the West.
Like many of his Taoist associates, nineteenth-century Taoist master Chao Pi Ch'en believed that life-force could be stored in the sex organs. The preservation of semen would lead a man to inner peace and physical well-being, while the loss of semen would throw his body into a world of chaos and exhaustion. He refers to sexual energy being stored in measurements called chu:
"A practiser should regard his body as a country and the generative force as its population. Unstirred generative force ensures security for the population, the fullness of spirit and (vital) breath increases the prosperity of the country. ...
If the generative force is gathered for a hundred (successive) days, sixty-four chu [measures] of vitality are gained and a unit of positive principle is produced; this is like "adding fuel" to feed and prolong life.
With the same determination, if the generative force is gathered for another hundred days an additional sixty-four chu [measures] of vitality are gained while the positive principle is increased to two units; the body now becomes very strong and all ailments vanish.
If the gathering of generative force continues for another hundred days an additional sixty-four chu [measures] of vitality are gained with the positive increased to three units; all cavities in the body are cleared for rejuvenation, and the practiser's steps are light and quick with clear and good hearing."
Master Chao explained that vitality in the form of sexual energy or (ching or jing) continues to increase naturally until the age of 16. After that, if the sexual energy is not properly conserved and transformed, a man loses sixty-four chu every 8 years of his life. The healthy balanced body is thought to have 384 chu.
By Chao's measurements, I'm pretty sure by the age of 24, I was bankrupt.
Western science hasn't gotten very far in proving any of the Taoist theories when it comes to sexual energy.
Some of the closest concrete studies I've found were conducted on nematodes—manipulating the male specimens such that they would no longer produce sperm. The results were definitive and quite surprising. The New York Times republished the study commenting:
"When he experimentally manipulated males so that they lost their capacity to make sperm while retaining their taste for intercourse, the altered nematodes lived at least 50 percent longer than the normal, fertile males. The results suggest that creating sperm is far more difficult than scientists had imagined, demanding a diversion of resources that might otherwise go into assuring a male's long-term health."
The verdict is still out whether or not seminal retention can prolong a male human being's life. Obviously, if celibacy was all that was required, we probably would've noticed by now. But teachers like Mantak Chia say retention isn't enough. What is required is your ability to transform the conserved sexual energy into something far more precious.
I think after 8,000 years it's safe to say that the ancient Chinese masters weren't entirely accurate when they said that the transformation of sexual energy (jing) into spirit (shen) would lead to immortality. But today, what is far more reasonable an idea, and absolutely a firm belief amongst Taoist practitioners today, is that your sexual energy can be transformed to assist in the spiritual awakening process. And that becoming Immortal has nothing to do with the physical body, per se, but rather everything to do with the spiritual aptitude one may attain in their lifetime.
Whether enlightenment is your goal, or peak performance is your thing, or just feeling a little better is something you'd be interested in, do not underestimate this practice. I haven't become enlightened, but I have experienced a profound life transformation since those early years of bankruptcy.
If you're serious about learning how this technique can be practically applied, I wrote an introductory tutorial on bypassing ejaculation and prolonging lovemaking a few months back. You can check it out here: https://wearesacred.org/multiple-orgasms-for-men/
And if you're interested in the NY Times article: https://www.nytimes.com/1992/12/03/us/in-worm-at-least-making-sperm-is-found-to-shorten-a-male-s-life.html
Other resources: The Secrets of Cultivation of Essential Nature and Eternal Life by Chao Pi Ch'en