Acetyl L-Carnitine: How It Works, Benefits, Clinical Studies And Side Effects

Acetyl L-Carnitine: How It Works, Benefits, Clinical Studies And Side Effects

What is Acetyl L-Carnitine?

Acetyl L-Carnitine

It is an amino acid which is naturally produced by the body. The forms L-Carnitine and Acetyl L-Carnitine are interchangeable.

Function: It helps in the production of energy and improving functions of heart, brain and the muscles.

Acetyl L-Carnitine (ALCAR) is an amino acid, and the acetylated form of L-Carnitine. It is produced naturally in the body and is also available as dietary supplements. The human body can convert Acetyl L-Carnitine to carnitine and vice versa. The major role of acetyl L-carnitine is the production of energy. In addition to it, it also performs different functions inside the body. As a medication, acetyl L-carnitine is used to treat a variety of diseases. According to research, ALCAR has more bioavailability than L-carnitine and is superior to it because it is hydrolyzed more than L-carnitine in blood.

Benefits of Acetyl L-Carnitine for Increased Testosterone Receptivity

Contrary to other supplements which boost the levels of testosterone by increasing its production, ALCAR actually increases the receptivity of cells to testosterone, so that the available testosterone may have its maximum effect. Thus, through ALCAR athletes and bodybuilders can have the following benefits:

  • Increased energy levels
  • Enhanced exercise performance
  • Increased flow of blood to the heart and working muscles
  • Improved recovery post-exercise
  • Reduced damage to muscles
  • Protection against oxidative stress which may be induced by exercise
  • Reduced muscular fatigue
  • Increased muscle mass and strength

How Does It Work?

ALCAR might actually decrease the testosterone levels of your blood rather than increasing it. But, is that necessarily a bad thing? The end result which you are looking for is increased testosterone activity. It might occur through:

  1. Increased Testosterone level – so that more testosterone is available
  2. Increased Receptivity – so that testosterone is allowed to enter more cells, thereby allowing your body to utilize more testosterone

So, ALCAR actually increases the androgen receptors in the human body where testosterone binds and is permitted to enter the cells. Let’s say you have high levels of testosterone, but not enough receptors. After all receptors have been saturated with the hormone, the rest of the testosterone will just circulate in your body with nowhere to go.

Other Benefits

It can be used for:

  • Improving cognitive function in diseases such as Down’s syndrome, Lyme disease and alcoholism
  • Treating mental disorder such as depression, memory loss and Alzheimer’s disease
  • Treating male infertility
  • Treating Peyronie’s disease (a disease of the penis)
  • Improving circulation in the brain
  • Eliminating nerve pain due to drugs and diabetes
  • Maintaining proper function of the heart and brain
  • Producing energy
  • Treating male menopause
  • Improving memory in old people
  • Keeping blood glucose low
  • Promoting fat lossFood Sources of Acetyl L-Carnitine

Food Sources

Being an amino acid, ALCAR is abundantly found in red meat. Lesser amounts are found in dairy products, poultry and seafood.

Clinical Studies

In a human study, the participants were either given a L-carnitine (2gm/day for 3 weeks) supplement or a placebo. It was found that the carnitine supplementation significantly increased the number of androgen receptors in muscular tissue by carrying out muscle biopsies of the subjects.

Side Effects

ALCAR is quite safe to use by adults but it might cause the following side effects in some people:

  • Vomiting
  • Nausea
  • Upset stomach
  • Restlessness
  • Fishy odor of sweat, breath and urine

A word of caution

There is not enough research available to establish the safety of ALCAR for expecting and lactating mothers. So, it is best advised to avoid its use in such conditions. Other than this, people with the following conditions should be extra cautious while starting on ALCAR:

  • For people suffering from hypothyroidism, ALCAR may further reduce the hormonal levels of thyroid hormones, worsening the condition
  • People who have a history of seizures should refrain from using ALCAR. This is so because L-carnitine is reported to increase the severity of the seizures, whether taken orally or intravenously (IV). Because the two forms of carnitine are interchangeable and can be converted by the body, it is thought that ALCAR may have the same effects.


It is not always necessary to increase testosterone levels in order to use more of it. Your body can utilize more of your available testosterone by increasing the number of testosterone receptors present in your muscular tissue. This is exactly what ALCAR accomplishes. By increasing the number of receptors, your muscles will increase in strength, lean mass and endurance. On a safer note, just make sure to consult your doctor before starting on ALCAR supplementation either for reasons pertaining to medical treatment or physical fitness. Once you have the go ahead from your doctor, you can incorporate the supplements in your diet and look forward to a healthier, leaner and muscular body!