N-acetylcarnosine (2001-02, 2009, 2012, 2014) & cataracts


Learn more about treatment for cataracts.

A number of research studies over the years support the premise that n-acetylcarnosine in a 1% solution is effective in treating cataracts. Following are brief descriptions of studies undertaken in 2001, 2002, 2009, 2012, and 2014. Later studies investigated the mechanics of the process.


Researchers investigated the efficacy of n-acetylcarnosine (NAC) in a 1% solution in treating or reducing the risk of cataract.

The study evaluated changes in lens clarity in nearly 100 subjects, 1/2 control and 1/2 treated. There were two trials - a 2 month trial and a 6 month trial. The patients were evaluated at the beginning of the study with standard measurements of vision testing for cataract with ophthalmoscopy, glare test, slit-image and retro-illumination photography.

The patients had an average age of 65 years old. The patients in each trial were given NAC (26 patients), placebo (13 patients) or untreated (10 patients) (placebo & untreated were combined into the control group).

Over six months 41.5% of the eyes showed marked improvement in lens clarity; 90% of the eyes showed a gradual improvement in lens clarity, and 88.9% of the eyes showed improvement in glare sensitivity. In general the topographic studies showed less lens density and opacity in the posterior subcapsular and cortical morphological portions of the lens.

With the study extending over two years, the researchers could report that the NAC benefit continues and is sustainable. There were no instances of a worsening of vision and in most patients tolerance of the drug was good. This form of L-carnosine appears to be suitable for nonsurgical treatment for senile cataracts.

Published: Peptides, June, 2001


Researchers reported the efficacy of a 1% N-acetylcarnosine solution for 46 older patients who have cataracts - observing the degree of lens opacity/clarity after 6 months and 24 month periods.

In two related pilot trials patients with lens opacity were also tested with the same solution or a placebo, with evaluations at the beginning, and every two months for six months and in a separate trial, every six months for two years. The cataracts were assessed for vision sharpness and glare and were measured with stereo cinamatographic retro-illumination and slit-images.

After six months 90% of the patients who had received NAC showed improvement in vision sharpness, and 89% showed improvement in glare.

The improvements continued after 24 months' treatment with NAC and none had deterioration of vision - while in the control group there was significant worsening after 24 months compared to both the start measurements and the treated patients.

There were no reports of systemic or ocular side effects and the drops were well tolerated. The researchers concluded that NAC shows promise for treating and preventing cataracts.

Researchers: Babizhayev MA, et al, Innovative Vision Products, Inc., Delaware, USA

Published: Efficacy of N-acetylcarnosine in the treatment of cataracts, Drugs in Research and Development, 2002;3(2):87-103.

2009 This study was designed to substantiate and fuller examine the results found in a 2002 study on the effectiveness of 1% N-Acetylcarnosine in improving cataract.

The subjects were 75 patients ranging from 54 to 78 years of age with no history of cataract surgery or other vision conditions except cataracts and with vision of 20/40 or worse as well as 72 controls. The patients had reported symptoms of glare sensitivity and were looking for quick relief.

After nine months the researchers found that most patients' glare scores improved or returned to normal standards.

The researchers emphasized that only the natural form of NAC in L-isomeric form was used and claimed this was important for outcomes. They discussed the mechanisms of cataract improvement to include:

  • prevention of free-radical-induced negative effect on antioxidants in the lens (superoxide dismutase);
  • prevention of oxidation (carbohydrate & metal-catalyzed) on interactions with proteins in the lens;
  • non-enzyme induced bonding capacity of carnosine which in turn protects the lens crystalline struction (proteins) from being adversely changed;
  • free-radical scavenging action of aldehydes, lipid hydroperoxides, and oxygen radicals;
  • interaction between l-carnosine and proteasome activity; and
  • disaggregation of lens crystallins activity.

Researchers: Babizhayev MA, et al, Innovative Vision Products, Inc., DE

Published: N-Acetylcarnosine sustained drug delivery eye drops to control the signs of ageless vision: glare sensitivity, cataract amelioration and quality of vision currently available treatment for the challenging 50,000-patient population, Clinical Interventions to Aging, 2009


Previously the effectiveness of n-acetylcarnosine was demonstrated in preliminary research. Researchers have followed up with a phase 2 placebo-controlled and double-blind study to test the validity of pilot studies.

The study performed a high-performance liquid chromatography analysis to investigate how N-acetylcarnosine is absorbed into the lens of the eye and how it promotes the presence of l-carnosine in the vitreous.

The eye's ability to absorb l-carnosine activates the back of the hypothalamus (tuberomammillary activation) which regulates normal nerve functioning including that which processes sensory input to the retina.

The introduction of N-acetylcarnosine is found to not be toxic to the structure of the eye, reduces inflammation, and may be a useful tool in vitreo-retinopathy surgery, and may be found to protect photoreceptor cells due to its antioxidant-like behavior.

Authors: M. A. Babizhayev, I.P. Khoroshilova-Maslova, A. Kasus-Jacobi

Published: Novel intraocular and systemic absorption drug delivery and efficacy of N-acetylcarnosine lubricant eye drops or carcinine biologics in pharmaceutical usage and therapeutic vision care, Fundamental & clinical Pharmacology, October, 2012.


Researchers investigated the effect of combining N-acetylcarnosine, previously shown to impact lens clarity, with D-pantethine on a 1-to-1 ratio. D-pantethine is a two-molecule form of vitamin B5 (pantothenic acid).

Lab animals with cataracts induced by UV light received a 5% mixture of the above combination either into the eyes or into the body cavity. It was found that such treatment inhibited the formation of cataracts. After the 82nd day of treatment the protective effect of the combination increased significantly. The researchers measured the results using gel permeation chromatography, a technique separates substances being analyzed on the basis of their relative size - in this instance looking at proteins that cause cataracts.

The researchers concluded that the combination inhibited development of cataracts caused by exposure to UV-type A radiation.

Published: (In Russian) [Deceleration of cataract development in rats under the action of N-acetylcarnosine and D-pantethine mixture], Eksperimental'naia i klinicheskaia farmakologiia, Vol. 77, 2014.