Discolored sperm, especially yellow sperm, typically raises alarms for a man; however, yellow semen usually has natural and benign causes. It is a common belief among many doctors that yellow sperm is rarely ever a sign of anything permanently damaging to the man or his fertility. In fact, the worst case scenario for a man who experiences a yellow semen color involves only a round of antibiotics. The most common causes of yellow semen are urine, age, diet and infection.

Foods that are rich in sulfur, like garlic, can make semen yellowish.

Semen is the reproductive fluid that contains sperm (spermatozoa). Sperm is the male sex cell that fertilizes the female ovum. It is made inside vessels of the testicles called seminiferous tubules. Later, it matures in the epididymis and vas deferens and travels through the urethra suspended in semen.

As a man ages, his semen may pick up a yellow tint.

As semen travels through the urethra before exiting the body, leftover urine in the urethra may exit with the sperm. This is very natural and a common occurrence among many men. It is likely to happen more than once, but does not require any action. A sign that the yellow semen was caused by urine is the semen being a very light tint of yellow as opposed to a darker shade of yellow. In most cases, this yellow tint goes unnoticed.

Eating lots of shallots can cause yellow semen.

Semen usually turns a more yellow color as a man becomes older. This change is gradual and typically does not mean that the semen will be yellow with every ejaculation. In most cases, the semen will appear to be more yellow after an older man goes longer stretches without ejaculation; however, this may also happen with a younger man at times. There is usually no need for any action as the sperm is still healthy and viable.

Multivitamins can cause a change in semen color.

A man’s diet affects the color of his semen as well. Food especially high in sulfur can cause yellow semen. The main kinds of food that contain sulfur and may change semen yellow include chives, onions, shallots and garlic. This also includes medications and multivitamins, which may also cause the semen to turn a light yellow color. It is entirely normal for this to occur, and it is not necessary to discontinue the diet.

Another common cause for yellow semen is infection. This is the first assumption of many men, and most doctors believe it is more likely to be the cause with younger men. Other signs that the yellow semen is a result of infection include greenish tints, a foul odor, and pain in the genital area. The most common infection is epididymitis, which is caused by prostate infection and can be easily cured with a round of antibiotics. Other infections, such as those caused by sexually transmitted diseases (STD) are also typically eliminated with antibiotics.