RSP Nutrition L-Carnitine Liquid Formula Review – How Does it Compare

RSP Nutrition L-Carnitine




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  • Contains L-Carnitine
  • Which is a good thing
  • and that is about it


  • Not the greatest formula
  • Other fat burners preferred

RSP Nutrition – L-Carnitine Liquid Formula Review

L-Carnitine is being sold hard these days. A few years ago the supplement company mafia was a bit half-hearted about it.

If something didn’t melt, shred, explode or destroy your fat the marketeers found it tough to sell it convincingly.

Saying “it helps transport long chain fatty acids into the mitochondria of cells” just didn’t have the same ring to it.

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Since they’ve cottoned on to the fact that people don’t believe a word of their sh!t anyway, said companies have dialled it back a bit, letting science and reason do much more of the talking.

Customers are also more willing to accept that fat loss and muscle gain are not races, won by the person who scoffs as much caffeine and protein as possible.

Slow and steady wins the race (well, most of the time).

And that’s really where L-Carnitine shines. Scientific research has backed it up, but like most things in this life, it’s your own consistency that’s going to make it work.

What Are The Benefits of L-Carnitine?

L-Carnitine has been the subject of study for decades to this point, but it wasn’t until a few years ago that we really started to understand how to use it as a supplement.

It’s in our diets in small amounts – meat particularly – and we can synthesize it ourselves, so it’s rare to find someone who’s deficient. Even vegans seem to be able to use it more efficiently and thus avoid any problems.

RSP's new Liquid Carnitine

It’s made of two amino acids: methionine and lysine, but it’s more like a B vitamin itself.

When we’re engaged in low intensity activity, l-carnitine helps form an enzyme that brings long chain fatty acids through cell membranes to the mitochondria so they can use it as fuel.

During higher intensity activity it forms acetylcarnitine, which is used to create a reservoir of coenzyme-A (CoA).

This allows the fat transportation to continue into high intensity exercise while keeping more glycogen in storage.

A few things happen as a result:

  • You extend the duration of fat burning
  • You reserve glycogen for higher intensity exercise
  • You delay lactic acid production and therefore fatigue

Our bodies can hold about 20 grams of carnitine, 90% of which is stored in muscle tissue. Therefore, if we can saturate our muscles to their highest potential carnitine content, we can burn more fat and exercise for longer.

That is the objective when supplementing with L-Carnitine.

As previously mentioned, scientific studies haven’t always shown success. Recently however, it has been proven that carnitine only enters muscle tissue when mediated by insulin.

It is therefore necessary to trigger the release of insulin, either via carbohydrates or leucine consumption, to absorb the carnitine into the muscles.

Carbohydrates will trigger a stronger insulin response, and of course the simpler the carb, the faster it will be.

That brings me to the next section, dealing with how to use L-Carnitine for best results.

How To Make the Most of L-Carnitine Supplements

Perhaps the most interesting result that came out of the UK studies in the mid twenty-teens was the prevention of fat accumulation, even during a caloric surplus.

I’ll explain.

Both the test group and the placebo group in the main study were trained athletes.

They drank a carbohydrate drink (plus L-Carnitine in the test group) that was several hundred calories over their maintenance calories.

In other words, they were in calorie surplus, which would ordinarily lead to weight gain, no matter how much exercise was being done.

And that’s exactly what happened to the control/placebo group.

They gained an average of 5 lbs over the course of the study.

The test group, however, kept the weight off. The only possible reason was that the L-Carnitine being absorbed alongside the carbohydrate drink was offsetting the energy difference.

The study was 24 weeks long. The weight gain in the control group wasn’t a lot considering the time frame but the results are still telling.

The follow-up study corroborated the results of the first and even highlighted some genetic signalling that tied l-carnitine supplementation with fat burning pathways in the body.

From the results of these studies, empirical evidence and observations, you can understand the best ways to implement carnitine supplementation.

Post-workout with Fast Carbs or Leucine

Following an intensive workout is the best time to consume some high GI (fast) carbohydrates as it replenishes the stores that have been used during training.

At the same time, muscle tissue is primed for nutrient uptake, so when your post-workout fast carbs trigger an insulin spike, it will not only help the storage of said carbs as glycogen in the muscles but it will help the uptake of several other nutrients, including L-Carnitine.

Together with you post-workout carbohydrate, consuming protein, l-carnitine and creatine will help all of these supplemental nutrients be stored for your next workout.

Straight glucose or dextrose is the best form of fast carbohydrate to eat/drink after working out because it can be absorbed directly by the muscles.

Sweets like gummy bears, twizzlers and donuts can be useful post-workout.

Despite the evidence for this, some people don’t want to consume high GI carbs post-workout.

The other option is to consume leucine as it triggers a similar insulin response.

Taking your l-carnitine with leucine should therefore also be effective.

Carb rich lunch

With Carb Rich Breakfast or Lunch

It’s best to split your daily total dosage of l-carnitine into a couple of servings. The post-workout dose is excellent, but you can also take some with breakfast or lunch, or both if you are on a rest day.

Again the insulin response mediates the uptake of carnitine into the muscles.

How Much L-Carnitine To Take?

I take around 3000mg per day, sometimes 4500mg.

The scientific literature is quite comprehensive and there has been no reported adverse effects so far.

As with most amino acids and amino-acid like compounds (l-carnitine is the latter), singular high doses can upset the stomach, hence splitting the dose into 2 or three across the day.

Most people seem to respond well to 1500mg servings, twice a day.

RSP Nutrition’s liquid formula, as well as other companies’ liquids, are easy to digest. What’s more, the dose timing is easy because the liquid gets into your system fast.

That means when you consume your liquid carb drink, fast sugar food or leucine, you can pretty much take the two together.

Man drinking RSP L-Carnitine

What’s The Verdict – Does RSP L-Carnitine Liquid Formula Work?

This – and any l-carnitine supplement – is a great tool for helping you to:

  • reduce your body fat level
  • control your body fat levels
  • improve your performance
  • reduce fatigue and perceived effort

The beauty of l-carnitine is that it can be useful to prevent fat accumulation even in moderate calorie surplus. That is in fact the very outcome of those groundbreaking studies.

With calories at maintenance it will help your body prioritize fat as the source of fuel for longer during exercise, reserving stored muscle glycogen for intensive work.

That fat burning extension reduces the load on your anaerobic respiration system, thus delaying, or at least reducing, the production of lactic acid. That’s where l-carnitine’s performance enhancing aspect lies.

Less lactic acid = less muscle fatigue = improved physical performance.

If you want to spend any time in severe carbohydrate restriction, then l-carnitine still works, mediated instead by protein induced insulin release.

Perhaps the main thing to remember when using l-carnitine is that it takes long-term use to get results. Remember that one of the studies was 24 weeks long.

Of note during the study was that the results at 12 weeks did not show significant success compared with the last measurements at 24 weeks. And the measurements were intensive as well – involving muscle biopsies and many other parameters.

The point is, dosage has to be consistent and long term, and used as part of a lifestyle involving a healthy nutritional plan and exercise program.

Many bodybuilders and competition athletes will use l-carnitine for long stints throughout the year, particularly when they are trying to reduce their body fat percentage leading up to the time of their competition.

It may not suit you to use the supplement all year long, partly because there are times when you will want your body to access your glycogen stores more readily, when you are looking to get maximum output from your muscles.

The reduction in maximum power potential is slight conjecture on my part, but it follows considering the effect muscle carnitine has on prolonging fat driven ATP production.

Fat is an incredibly efficient fuel source but it cannot yield its energy as quickly as carbohydrate can.

That said, if you exercise with enough intensity, your system will have no choice but to dig into its glycogen stores, especially where resistance training is concerned.

In the end, if you’re looking to preserve muscle mass while reducing your overall weight, these liquid L-Carnitine supplements are worth a go.

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