If you got rid of it, why put it back?
 Contrary to what we learn in biology, urine isn't a dirty byproduct of intestinal work. Instead, it's a highly usable, sterile fluid that comes from the kidneys. The main function of the kidneys is to balance and filter the blood. Urine, the kidneys' byproduct, is made from life-sustaining ingredients, like vitamins, minerals, proteins, enzymes, hormones, antibodies, and amino acids - estimated to be thousands of compounds in all. For example, urine, also the primary component of amniotic fluid, contains DHEA (the wonder steroid heralded with antiaging and anticancer properties), allantoin (added to creams and ointments to promote wound healing), factor S (used to naturally induce sleep), gastric secretary depressants (which combat ulcer growth), urokinase (an enzyme known to dissolve blood clots), and, of course, urea (a key constituent in many antibacterial substances). Some scientists even suggest that uric acid, the most touted property of urine, may be an instrumental ingredient that allows humans to live longer than most other mammals
has anticancer agents, such as DHEA, retine, antieoplastons, uric acid, H-11 extract, and HUD (human urine's derivative), but it also contains the antibodies to HIV-1, a fact discovered in 1988 by Dr. Alvin Friedman Kien at the New York University Medical School. Urine therapy and yoga tradition 

Let's go back to the Indian history, where even much older texts describing the practice of urine therapy are available. A presumably 5,000-year-old document has been found which describes the practice of urine therapy in different respects. In this document, there are many references to herbs and medicines still used in present day Ayurveda. This document consists of 107 verses (slokas), is called Shivambu Kalpa Vidhi ('the method of drinking urine in order to rejuvenate'), and is part of a document called Damar Tantra. (The entire text can be found in Chapter 7 of The Golden Fountain) Shivambu literally means the water of Shiva, the highest god in the Indian pantheon. The name Shiva means auspiciousness. In India, at least among urine therapists, one often speaks of drinking Shivambu, which simply means drinking the water of auspiciousness. They also sometimes jokingly refer to it as 'Morarji Cola', as India's former prime minister Morarji Desai used to practice urine therapy. He openly advocated this therapy and said India would be well off when more people would use this extremely inexpensive and effective way of treatment. These are the opening verses of the Damar Tantra text, in which the god Shiva begins to speak with his wife Parvati: 

Verses 1 - 4: 

"Oh Parvati! (The God Shiva speaks to his wife Parvati.) Those who practice this method can enjoy the fruits of their meditation and this method. For this, certain actions have been recommended along with certain types of utensils. The Shivambu is to be drunk from pots made of gold, silver, copper, brass, iron, tin, glass, earth, bamboo, bones, leather, or a bowl made of plantain leaves. The urine should be collected in any one of the above mentioned utensils and should be drunk. However, earthen pots are the best for use." 

Practical instructions are given on how to collect and ingest urine, and advice on what is best to eat if you drink your own urine. It has to be kept in mind, however, that this document was written for those who practice yoga, work intensively with their body and soul and adapt their food to this lifestyle. Nevertheless, the following verse contains some helpful general guidelines for everyone who uses urine therapy. 

Verse 5: 

"The follower of the therapy should avoid pungent, salty ingredients in his meals. He should not over-exert himself. He should follow a balanced and light diet..." 

Urine was equated with a divine drink which had the power to exterminate all kinds of illnesses and ailments. The following verse suggests that physical purification is connected with a life of meditation. 

Verse 9: 

"Shivambu is a divine nectar! It is capable of abolishing old age and various types of diseases and ailments. The follower should first ingest his urine and then start his meditation." 

As said before, drinking urine is not the only way to apply urine therapy. A number of verses discuss the importance of massaging with urine. For example: 

Verse 48: 

"Shivambu should be applied to the whole body. It is exceptionally nourishing, and can relieve all ailments." 

Verse 87: 

"Oh Parvati! If he massages his body thrice a day and night with Shivambu, his countenance will be shining and his heart will be strong. His body and muscles will be strong. He will float in pleasure." 

This last text is special because it connects physical purification with purity of spirit and state of mind. Verse 87 is an especially good example of this belief. The hormonal component seems to have a positive effect on the state of mind. Various people with whom I have spoken felt noticeably more emotionally stable, high-spirited and vital after they started urine therapy. Probably this partly has something to do with the aforementioned hormone melatonin. 

Other ancient texts which are part of the religious and spiritual heritage of India also contain fragments about and refer either to urine therapy or to 'amaroli' ('nectar of immortality'). A few examples: 

Hatha Yoga Pradipika 3;96-97: 

"In the doctrine of the Kapalikas, amaroli is the drinking of the midstream, leaving the first for it is too pungent (too much bile) and the last, which is useless. He who drinks amari, snuffs it daily, and practices vajroli, is said to be practicing amaroli." 

Gyanarnava Tantra, Chapter 22: 

"After realizing the exact knowledge of dharma and adharma, every aspect of the world becomes holy - stool, urine, ovum, nails, bones, are all holy things in the sight of that person who has explored mantra. O Parvati, different deities are living in that water from which urine is made, then why is urine said to be contaminated?" 

Harit, Chapter 1 on Urine: 

"Human urine is basic, bitter and light. It destroys diseases of the eyes, makes the body strong, improves digestion and destroys coughs and colds." 

Bhawa Prakasha, Verse 7, Chapter on Urine: 

"Human urine destroys poison, properly used it gives new life, purifies blood, clears skin troubles, is sharp in taste and contains many salts." 

Yoga Ratnakar, Mutrashtakam Verse 11: 

"Human urine controls bile in the blood, destroys worms, cleans intestines, controls cough and calms nerves. It is sharp in taste, destroys laziness and is an antidote to poisons."