Usage, dosage, how much to take
Half or one carnosine capsule before or with breakfast a few times a week, or as directed by your qualified health consultant. The capsule can be opened by pulling on each side and emptying some of the contents in a cup.

Q. Dr. Kyriazis, a leading anti-aging MD in the UK, based on his human trials of carnosine and current research states the current marketed dosing is based upon studies done with mice and cancer patients and  that dosage of 100-200 mg are effective in humans while doses greater than 500 mg show adverse and reverse effects. Obviously there is a dosage transition area between 200 and 500. This doctor recommends ideally - 100 to 150 mg a day. Your comment on this article would be highly appreciated.
    A. Nobody knows for sure what the ideal dosage is in humans, and every person is different. However as a general guideline, I believe the lower amounts are probably just fine and people can open a 500 mg capsule and take a portion of it a few times a week.

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Alzheimer's disease prevention
Life Sciences. 2004. Anti-crosslinking properties of carnosine: significance of histidine. Carnosine is a potential treatment for Alzheimer's disease. There is evidence that it prevents oxidation and glycation, both of which contribute to the crosslinking of proteins; and protein crosslinking promotes beta-amyloid plaque formation.

Anti-aging, longevity
Maturitas. 2016. Carnosine and the processes of ageing. It has been suggested that the endogenous dipeptide carnosine, also available as a food supplement, possesses anti-ageing activity and may achieve its reported age-alleviating effects via inhibition of the mechanistic target of rapamycin and carbonyl scavenging.

Antioxidant, benefit for athletes
Acta Physiol Hung. 2014. Influence of l-carnosine on pro-antioxidant status in elite kayakers and canoeists. Carnosine has an antioxidant role and accounts for about 10% of the muscle's ability to buffer the H+ ions produced by high intensity exercise. Fourteen male athletes from the Polish national kayak and canoe teams participated in placebo-controlled and cross-over study. The athletes were supplemented with 4 grams each day carnosine for 14 days. Blood samples were collected before and 30 min, 24 h and 48 h after 2000 m exercise trial. In blood, hydrogen peroxide (H2O2), nitric oxide (NO), total (GSHt) and oxidised glutathione (GSSG), antioxidant status (APO) and superoxide dismutase (SOD) were determined. There were not observed statistically significant differences in exercise-induced changes in H2O2 and NO concentrations and SOD activity after carnosine intake. However, carnosine prevented an increase in 8-isoprostanes, 3-nitrotyrosine and GSSG concentrations as well as elevated redox status at post-exercise period. Oral supplementation significantly attenuated exercise-induced glutathione loss, reduced oxidation/nitration markers concentration and SOD activity. These results suggest that carnosine could provide antioxidative protection for highly trained athletes.

Anti-aging studies, lifespan, longevity
Glycation plays important roles in aging and in diabetes and its secondary complications. Carnivorous diets contain this potential anti-glycating agent, whereas vegetarians may lack intake of the dipeptide.

Biochemistry 2000. Use of carnosine as a natural anti-senescence drug for human beings. Apart from the function of protecting cells from oxidation-induced stress damage, carnosine appears to be able to extend the lifespan of cultured cells, rejuvenate senescent cells, inhibit the toxic effects of amyloid peptide (A beta), malondialdehyde, and hypochlorite to cells, inhibit glycosylation of proteins and protein-DNA and protein-protein cross-linking, and maintain cellular homeostasis. Also, carnosine seems to delay the impairment of eyesight with aging, effectively preventing and treating senile cataract and other age-related diseases.

Biochem Biophys Res Communications. 2004. l Carnosine reduces telomere damage and shortening rate in cultured normal fibroblasts. Telomere is the repetitive DNA sequence at the end of chromosomes, which shortens progressively with cell division and limits the replicative potential of normal human somatic cells. l Carnosine, a naturally occurring dipeptide, has been reported to delay the replicative senescence, and extend the lifespan of cultured human diploid fibroblasts. In this work, we studied the effect of carnosine on the telomeric DNA of cultured human fetal lung fibroblast cells. Cells continuously grown in carnosine exhibited a slower telomere shortening rate and extended lifespan in population doublings. We suggest that the reduction in telomere shortening rate and damages in telomeric DNA made an important contribution to the life-extension effect of carnosine.

Maturitas. 2016. Carnosine and the processes of ageing. It has been suggested that the endogenous dipeptide carnosine, also available as a food supplement, possesses anti-ageing activity and may achieve its reported age-alleviating effects via inhibition of the mechanistic target of rapamycin and carbonyl scavenging may be involved.

Carnosine helpful in autism
From the day she was born, Betty seemed different from other infants. At an age when most infants enjoy interacting with people and exploring their environment, Betty sat motionless in her crib and didn't respond to rattles or other toys. It wasn’t too long before Betty was diagnosed with autism. Unfortunately, modern medicine has little to offer as a cure for this condition. But supplements may be helpful. Researchers at the Autism and Epilepsy Specialty Services in Lake Bluff, Illinois, investigated 31 children with autism in an 8-week, double-blinded study to determine if carnosine would result in changes. The children received 800 mg a day and were compared with a group of children on placebo. After 8 weeks, children given carnosine showed statistically significant improvements on several tests including an improvement in vocabulary and recognizing a picture.
     Dr. Sahelian says: L-carnosine is sold in health food stores most commonly in capsules of 500 mg. It would be worthwhile to try 100 to 200 mg of this nutrient before breakfast and lunch for a few weeks under a pediatrician’s supervision. The dose would be much less than in adults.

Q. Would Carnosine in a liquid form be effective in the treatment of autism. Would it tend to degrade into alanine and histidine - and/or would this be a benefit or problematic? Would a liquid form still be of benefit to autism?
    A. I have not seen studies regarding the liquid form of carnosine, I don't see how it could have advantages over the carnosine capsules. In fact, a capsule can be opened and part of the carnosine used in water or juice.

Cancer chemotherapy drug, protection from heart damage
Influence of carnosine on the cardiotoxicity of doxorubicin in rabbits.
Pol J Pharmacol. 2003.
The aim of this study was to establish the effect of naturally occurring antioxidant carnosine on the doxorubicin induced cardiotoxicity in a rabbit model. The histopathological studies revealed smaller damage of cardiac muscle in rabbits which received doxorubicin with carnosine in comparison to animals receiving doxorubicin alone. Carnosine seems to protect heart tissue during doxorubicin administration.

Ovarian cancer
Anticancer Res. 2016. L-Carnosine Prevents the Pro-cancerogenic Activity of Senescent Peritoneal Mesothelium Towards Ovarian Cancer Cells. L-carnosine may be a valuable anticancer drug, especially in the context of prevention and therapy of intraperitoneal ovarian cancer metastasis.

Diabetes research
Diabetes. 2005. Carnosine as a protective factor in diabetic nephropathy: association with a leucine repeat of the carnosinase gene CNDP1. DNA polymorphisms were determined in 135 case (diabetic nephropathy) and 107 control (diabetes without nephropathy) subjects. The effect of carnosine on the production of extracellular matrix components and transforming growth factor-beta (TGF-beta) after exposure to d-glucose was studied in cultured human podocytes and mesangial cells, respectively. Carnosine inhibited the increased production of fibronectin and collagen type VI in podocytes and the increased production of TGF-beta in mesangial cells. Diabetic patients with the CNDP1 Mannheim variant are less susceptible for nephropathy. Carnosine protects against the adverse effects of high glucose levels on renal cells.

Eyesight and vision, cataracts
Carnosine eye drops could be used as a potent antioxidant to reduce certain types of vision disorders. Those who wish to improve distant and close vision, along with day and night vision, should consider Eyesight Rx, a tablet that melts under the tongue and improves eyesight within a few days.

Topical N-Acetyl-carnosine eyedrops shows potential for the treatment and prevention of cataracts. A study with rabbits indicates that carnosine reduces the cardiac toxicity from the use of the chemotherapeutic drug doxorubicin. Another area of potential benefit for carnosine is diabetic nephropathy.

I am trying to locate at least 2% N-Acetyl Carnosine eye drops for my 13 year old English Setter who, unfortunately, now has mature cataracts and is virtually blind. The 1% drops by Bright Eyes III were a waste of my money. Please, if there is anywhere that i can purchase NAC liquid drops, let me know.
    A. Since products that enter the eye have to be manufactured in a sterile manner, we are cautious in recommending any companies that make NAC liquid drops since we cannot be sure of their manufacturing and quality control processes.

Efficacy of N-acetyl- carnosine in the treatment of cataracts. Drugs R D 2002.

Kidney disease
Dietary supplementation of L-carnosine prevents ischemia/reperfusion-induced renal injury in rats.
Biol Pharm Bull. 2005.
Our findings strongly suggest that Lcarnosine supplementation is useful as a prophylactic treatment in the development of the ischemic acute renal failure.

Am J Physiol Regul Integr Comp Physiol. 2004. Dose-dependent effects of L carnosine on the renal sympathetic nerve and blood pressure in urethane-anesthetized rats. The physiological function of carnosine (beta-alanyl-L-histidine) synthesized in mammalian muscles until recently has been unclear. Previously, we observed that intravenous injection of carnosine suppressed renal sympathetic nerve activity (RSNA) in urethane-anesthetized rats, and carnosine administered via the diet inhibited the elevation of blood pressure (BP) in hypertensive rats. To identify the mechanism, we examined effects of IV or intra-lateral cerebral ventricular (LCV) injection of various doses of carnosine on RSNA and BP in urethane-anesthetized rats. Lower doses of carnosine significantly suppressed RSNA and BP, while higher doses elevated RSNA and BP. These findings suggest that low-dose carnosine suppresses and high-dose carnosine stimulates RSNA and BP, that the SCN and histaminergic nerve are involved in the activities, and that carnosine acts in the brain and possibly other organs.

OCD, obsessive compulsive disorder
Hum Psychopharmacol. 2017. L-carnosine as an adjuvant to fluvoxamine in treatment of obsessive compulsive disorder: A randomized double-blind study. Dysregulation of glutamate is implicated in the pathogenesis of obsessive-compulsive disorder (OCD). Consistently, glutamate-modulating agents, such as riluzole and memantine have been used in OCD treatment. Here, we assessed the efficacy of L-carnosine as adjuvant to fluvoxamine in OCD treatment. Forty-four patients diagnosed with moderate to severe OCD were recruited in a randomized double-blind trial. Patients received either L-carnosine or placebo as adjuvant to fluvoxamine for 10 weeks. L-carnosine results in significant reduction of obsessive-compulsive symptoms when used as an adjuvant to fluvoxamine.

Parkinson's disease
Aging Dis. 2017. On the Relationship between Energy Metabolism, Proteostasis, Aging and Parkinson's Disease: Possible Causative Role of Methylglyoxal and Alleviative Potential of Carnosine. Recent research shows that energy metabolism can strongly influence proteostasis and thereby affect onset of aging and related disease such as Parkinson's disease (PD). Changes in glycolytic and proteolytic activities (influenced by diet and development) are suggested to synergistically create a self-reinforcing deleterious cycle via enhanced formation of triose phosphates and their decomposition product methylglyoxal. Carnosine, a naturally-occurring dipeptide, may ameliorate methylglyoxal-induced effects due, in part, to its carbonyl-scavenging activity.

Smell, olfactory sense
Is carnosine a naturally occurring suppressor of oxidative damage in olfactory neurones?
Rejuvenation Research. 2004.
Neurons from olfactory lobes of Alzheimer's patients exhibit oxidative stress and it is well known that olfactory dysfunction frequently accompanies neurodegeneration. The olfactory lobe is normally enriched in carnosine, a relatively non-toxic (and sometimes abundant) dipeptide which possesses functions (anti-oxidant, antiglycator, scavenger of zinc and copper ions, toxic aldehydes and protein carbonyls) that are likely to suppress oxidative stress. It is suggested that its therapeutic potential should be explored in olfactory tissue.

Testimonial
I have stumbled across your site multiple times and your information seems to hold true with my experiences with some of the herbs, vitamins, supplements you discuss. I just saw that you mentioned there may be a link between carnosine and smell. Earlier today I purchased some before reading about it on your site and knowing only of potential stomach liver and learning benefits and the moment I took it I noticed my sense of smell became much more keen as it used to be. Just wanted to share the info with you and thank you for the info you provide as I can see that you are very knowledgeable.

Stem cells ?
Q. According an email I got from Dr. Al Sears -- the use of blueberries plus l carnosine resulted in a huge 80 percent increase in stem cell activity, he recommends dosage of 1000 mg a day. I prefer your dosages to be on the safe side.
   A. High doses can cause sleep problems which is counterproductive to good health.

Side effects, safety, risk
High doses can cause insomnia and difficulty with sleep. A feeling of being very stimulated can occur.

Q. I get an allergic response (sinus problems, skin rash) to oral carnosine at 1000mg, I could lower the dose but I'm curious why this happens (some people I know take 1000 mg for antiaging (antiglycation) effects). I'm not allergic otherwise to any food. I believe it's a histamine release but I find it strange.
    A. Carnosine converts into histidine which converts into histamine. Perhaps too high of a carnosine dose can shift the metabolic pathway towards histamine. I don't think more than 100 mg of carnosine is needed on a regular basis. Too much of a good thing can sometimes be harmful.