https://www.exercise.com/supplements/cystine
Cystine

Cystine

Aid Overall Health

Among the many amino acids used by the human body for a variety of purposes is an acid known as L-cystine. This particular amino acid should not be confused with L-cysteine, even though the latter is a derivative of the former.

In its purest form L-cystine is a nonessential amino acid, meaning it can be synthesized by the body from the combination of other substances. L-cystine’s importance is directly tied to its ability to help maintain a proper redox state at the cellular level.

The L-cysteine derivative is produced in a more stable form called N-Acetyl-Cysteine (NAC), and is more common as a nutritional supplement than straight L-cystine. That's because NAC also contains high amounts of anti-oxidants than are beneficial in helping rid the body of free radicals.

Control of free radicals is believed to help ward off heart disease, vascular disorders, many types of psychological disorders, and even some kinds of cancers. 

Not all types of physical activity are suitable for everyone. Users take training advice at their own personal risk.

Summary

L-cystine Benefits When L-cystine is used as an ingredient in a dietary supplement it is most often found in bodybuilding supplements due to its ability to help heal wounds. It is believed that the same wound healing properties also apply to rebuilding worn and damaged muscle tissue after ... more

L-cystine Benefits

When L-cystine is used as an ingredient in a dietary supplement it is most often found in bodybuilding supplements due to its ability to help heal wounds. It is believed that the same wound healing properties also apply to rebuilding worn and damaged muscle tissue after strenuous exercise.

However, those beliefs have not been conclusively proven in scientific studies. Furthermore, the fact that it can be synthesized from other substances means it may not even be necessary as a supplement.

L-cystine can be purchased as a standalone supplement for the purposes of wound recovery and increased metabolism. The effect of this amino acid on metabolism may turn out to be a much better reason to include it as an ingredient in a bodybuilding supplement.

Proper metabolism helps the body make the most of the food we ingest.  It stands to reason that a properly functioning metabolism would help bodybuilders gain the maximum benefits of their diet and exercise regimens.

L-cystine Side Effects

Used in moderation, doctors agree that L-cystine is generally safe. However, some very notable side effects have been noticed in certain users.

The most common of those sad affects is a condition where cystine stones build up in the kidneys and must be expelled through the urine. These stones are similar to kidney stones but tend to be smaller and less troublesome. Nonetheless, a buildup of these stones caused by excessive use of L-cystine can be rather uncomfortable.

The second side effect is something more serious; it's known as Fanconi syndrome. This is a kidney disease in which nutrients such as amino acids and glucose are passed from the body in urine rather than being reabsorbed into the system. The disease can be the precursor to more significant diseases including stunted growth, rickets, and osteamalacia.

 Other less threatening side effects include nausea, vomiting, headache, and slightly lower blood pressure.

L-cystine Efficacy

The jury is still out on the legitimacy of using L-cystine as either a standalone supplement or an ingredient in other supplements. The reason such speculation exists lies and the fact that L-cystine deficiency is rarely seen in the western world. The FDA does not regulate L-cystine supplements.

When it is seen in a clinical setting, it is usually among vegetarians whose intake of methionine and cysteine is abnormally low. For the rest of us, this amino acid is found in abundance in many of the foods we eat such as cheese, yogurt, pork, chicken, and several of different kinds of oats. Additionally, since both L-cystine and the NAC derivative can be synthesized by the body from other substances, most healthy people have an adequate supply without ever taking supplements.

While many supplement makers believe L-cystine is a necessary and healthful ingredient there are an equal number who believe just the opposite. It seems reasonable that individuals considering purchasing a supplement with this amino acid included should not make a decision based solely upon having as an ingredient.

L-cystine Dosage

Recommending a specific daily dosage of this amino acid is a difficult task due to the previously mentioned facts. What may be an excess dosage for one individual may be just right for another.

The one thing can be said for certain is that individuals who decide to take L-cystine as a supplement need to follow dosage instructions exactly as written on the package. All amino acids in the body require a delicate balance in order to work properly and avoid negative side effects. Following dosage instructions is critical to maintaining that balance.

As a standalone supplement there are a handful of manufactures selling L-cystine at a dose of 500mg. There are a couple of medical web sites that recommend dosages somewhere between 250mg and 1,000mg. As a general rule it appears that users should not go above 1,000mg daily.

Looking for the right amino acid product? Use the supplement finder now!

Other

  • Side Effects
  • Other Names
  • Uses
Vomiting
Headaches
Low Blood Pressure
Nausea
Kidney Disease
Cystine Stones
Acetyl Cysteine, Acetylcysteine, Cysteine, Cysteine Hydrochloride, Cystine, L-Cysteine, L-Cysteine HCl, NAC, N-Acetil Cisteína, N-Acetyl-B-Cysteine, N-Acétyl Cystéine, N-Acetyl-L-Cysteine, N-Acetylcysteine
Muscle Repair
Wound Healing