L-Carnosine: Benefits, Side Effects, Best Time to Take It & More

L-Carnosine

(Carnosine)

Evidence: Reasonable
Possible Benefits: Reasonable
Safety: Reasonable

What is L-carnosine?

L-carnosine is a non-essential amino acid that can be synthesized in the body from beta-alanine. As a supplement, most people use it for improving exercise performance and gaining muscle mass. While L-carnosine can have these benefits, they are relatively small. This article is about the main benefits of L-carnosine, its potential side effects, the best time to take it, and more.

What does L-carnosine do for the body?

L-carnosine is a non-essential amino acid that can be synthesized in the body from beta-alanine, so you do not need to consume it to survive. However, this amino acid still plays a significant role in human health.

Carnosine helps buffer acid in muscles. This can increase exercise performance, especially when it comes to resistance training or anaerobic exercises.

This amino acid plays a role in healthy aging. It acts as an antioxidant, an antiglycation agent, and a chelator of toxins.

Carnosine is also found in the brain and is likely to impact cognition.

Possible benefits

The benefits mentioned below are dose-dependent. Generally, the higher the dose, the more pronounced the effects are. However, they do reach a plateau at a certain point. We will discuss the best dosing protocol later in this article.

Major benefits

Increased muscular endurance – Beta-alanine supplementation increases muscular endurance and time to exhaustion by about 2.85%. This effect was observed when exercising for 1-10 minutes and mainly applies to anaerobic exercise sessions (such as sprints and heavy resistance training). Since beta-alanine acts as a precursor to carnosine, L-carnosine itself is likely to have this effect as well.

Minor benefits

Reduced fatigue – This benefit only applies to exercise-induced fatigue.
Muscle growth – L-carnosine has a mild hypertrophic effect.
Fat loss – This benefit is mild and only applies to those who exercise.
Lowered blood sugar levels – This effect is likely indirect and caused by L-carnosine’s positive effects on overall health and increased exercise performance.

Possible side effects

These side effects are dose-dependent. The risk for them increases (often linearly but sometimes exponentially) as you increase the dose. Some of the side effects only apply to very high doses.

Nausea
Diarrhea
Taurine deficiency – Taurine and carnosine share the same transporter and should be kept in balance as too much of one can cause a deficiency in the other.
Paresthesia – This is a relatively harmless tingling feeling caused by high doses of L-carnosine. You can prevent this side effect by lowering the dose or spreading it evenly throughout the day.
Toxicity – While acute toxicity is extremely rare, taking high amounts of L-carnosine could lead to chronic toxicity and cause some health problems. To prevent chronic toxicity, it is best to stay below 2 grams a day unless you have a great reason to take more.
Contamination – Contaminated supplements are uncommon in the USA and other well-regulated countries. However, if you wish to buy products from China, India, or other countries without strict regulations, beware that the supplements may be contaminated. Either way, you need to choose the brand you order from wisely. It is highly recommended to check the certificates or read through some reviews for the specific product before you buy it. The FDA (Food and Drug Administration) has the power to regulate dietary supplements but can only do so after they have been on the market for a while. That’s because supplement companies are not obligated to announce to the FDA when releasing a new product on the market. The FDA has to discover the product and test it for potential impurities, which can take a lot of time. During that time, the supplement can be sold on the market even if it’s impure. Also, supplement companies can change their manufacturers without announcing it to the FDA.

Who should not take L-carnosine?

You should probably avoid taking the supplement if you:

experience a severe adverse reaction after taking the amino acid
do not exercise much
are on a tight supplement budget (since there are more cost-effective supplements on the market for most people)

Who will benefit the most?

You should consider taking the supplement if you:

consume very little protein (less than 0.3 grams/pound of body weight)
work out a lot and wish to optimize muscle growth
are on a plant-based diet
take taurine

How much L-carnosine should you take?

If you plan to take L-carnosine as a supplement, 500-1000 mg appears to be the best daily dose for most people. This amount should provide most of the benefits without meaningful side effects.

Some people may benefit from doses higher than 1000 mg. These include athletes and people taking high doses of taurine.

The upper safety limit for L-carnosine is not well-established. To stay on the safe side, don’t take more than 2 grams daily unless you have a great reason to do so. Higher amounts may cause problems if you take the supplement for a prolonged period.

Best time to take L-carnosine

Like most other amino acids, L-carnosine is water-soluble, so you don’t have to take it with food to absorb it well. To maximize absorption, take the supplement at least an hour before or after a meal so it doesn’t compete for absorption with other amino acids.

L-carnosine is often taken before a workout but it doesn’t have to be. When you take the supplement doesn’t have much impact on how beneficial it is if any.

Whether you take the supplement in the morning or the evening doesn’t matter much. It should not interrupt your sleep in any way.

If you practice time-restricted eating, take this amino acid during your eating window to guarantee it won’t break your fast.

Unless it feels too impractical, spread the daily dose into 2+ smaller doses throughout the day.

Interactions

Taurine
Taurine and L-carnosine share the same transporter and should be kept in balance as too much of one can cause a deficiency in the other.
Other amino acids
Essential and non-essential amino acids should be kept in balance as they act synergistically in many ways. Too much of one amino acid can sometimes cause side effects if there isn’t enough of another amino acid. For example, this principle applies to glycine and methionine, lysine and arginine, and the BCAA trio. There are many other proven and unproven examples. Food or a protein powder is usually a better choice for getting enough amino acids unless you have a specific goal in mind targeted by a particular amino acid/s.
Creatine
There is a tiny synergistic effect between creatine and L-carnosine.

Where to buy L-carnosine

Amazon is the best option for ordering L-carnosine supplements in most countries. They offer some very affordable products backed by many positive reviews. Also, you can choose from a wide range of brands without having to search through other markets on the internet.

Beware some brands display the dosage per serving instead of per pill or capsule. Therefore, you may accidentally buy something less potent than you intended. Do not fall for this marketing trick.

FAQ

You can take the amino acid daily and do not need to cycle it. However, it is certainly not a problem if you don’t take it daily. Not taking the supplement every once in a while could lead to better absorption. That is yet to be proven or disproven.

All of these options are fine. The two most important things to consider are the price and dosing. Powders are almost always the cheapest form. However, you may need a highly accurate scale to dose them correctly (preferably 0.001g). You can get one for as little as $20 from Amazon. Dosing the powders also takes some time that can add up over months or years. The disadvantage of capsules is that they often contain bovine gelatin, which rarely comes from an ethical source.

Yes. Most amino acids, including L-carnosine, absorb and digest well if you take them before falling asleep. The supplement should not impact sleep quality in any significant way.

This amino acid should not become harmful once it exceeds the expiration date but can lose potency over time.

Keep the supplement in a cold, dark, and dry place, and it should remain just as potent for many months or even years.

While toxicity is rare, too much L-carnosine in the system can cause some health problems, often related to taurine deficiency. It is best to stay below 2 grams a day to prevent these side effects.

You may need more of this amino acid if you:
– eat very little protein (less than 0.3 grams/pound of body weight)
– work out a lot and wish to optimize muscle growth
– are on a plant-based diet
– take taurine

You need to take the supplement for about 2-4 weeks to begin noticing the benefits related to increasing muscle carnosine levels.

You can easily find vegan-friendly L-carnosine pills and powders but always check the label to be sure. If you buy the amino acid in a capsulated form, beware that the capsules often contain animal-based gelatin. Instead, find a brand that puts its products into cellulose capsules.

Like most other amino acids, L-carnosine is water-soluble, so you don’t have to take it with food to absorb it well.

L-carnosine should not break a fast unless you take a very high dose at once. If you practice time-restricted eating, take this amino acid during your eating window so it doesn’t break your fast.

References

Most of the information provided in this guide is supported by scientific research that can be found and verified in the PubMed medical library. We highly encourage you to use the library to verify anything said in this article. We excluded from consideration studies that are either confounded or have a high conflict of interest.

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