Ultra KLB6 is a dietary supplement made for Holland & Barrett. It’s an updated version of an earlier product called Holland & Barrett KLB6.

Both versions of the product provide kelp, lecithin, Vitamin B6, and cider vinegar. The only difference between KLB6 and Ultra KLB6 is the ingredient quantities. The new version provides less kelp and more Vitamin B6.

Holland & Barrett isn’t the only company that has a “KLB6” supplement. A few other companies are selling them too. It’s also worth noting several companies that used to have KLB6 supplements appear to have given them up as a bad idea. That should tell you a lot.

I’m going to start this review by admitting Holland & Barrett Ultra KLB6 does not impress me. Neither do any of the KLB6 supplements distributed under other brand names such as Puritan’s Pride. Most of them are cheap to buy but they have so little to offer, I can’t see the point.

The fact that you are reading this review suggests you may be considering buying Holland & Barrett Ultra KLB6. Then again, you may only be trying to figure out what it’s supposed to do because Holland & Barrett doesn’t provide much information.

Regardless of your reasons for being here, this review will tell you the things you need to know and help you decide if Holland & Barrett Ultra KLB6 is a supplement you want to try.

I’m also going to suggest a better alternative if you decide you’d prefer to go with a different product instead.


Ultra KLB6: The Promised Benefits

  • Ultra strength dieters’ support formula
  • Easy to swallow coated caplets
  • The goodness of kelp, soy lecithin, Vitamin B6, and cider vinegar
  • Suitable for vegetarians & vegans


What Is Ultra KLB6 and How Does It Work?

Holland & Barrett Ultra KLB6 is a capsule-type supplement you take every day. It’s designed to be easy to swallow and is suitable for vegans and vegetarians but not for people who are allergic to soy.

The label describes it as a “dieters support formula” that “supports weight management.” That doesn’t tell you a lot.

The product description on the Holland & Barrett website isn’t much better but never mind. My ingredient evaluation will give you a better understanding of the things Ultra KLB6 can and cannot do.


Holland & Barrett Ultra KLB6 Ingredients

Three caplets provide:

Vitamin B6

Cider Vinegar



50 mg

240 mg

100 mg

600 mg


Ultra KLB6 Ingredient Abilities

This is a pretty simple formulation. There’s not a lot to worry about and Holland & Barrett states all the inclusion rates. When you are familiar with the ingredients, it’s not difficult to understand what the formulation can and cannot do.


​Vitamin B6 (50 mg)

Vitamin B6 is a water-soluble vitamin. Your body cannot store it so you need to consume Vitamin B6 every day.

Vitamin B6 is a key player in nutrient metabolism. It helps your body extract energy from food. That’s why it’s present in most good energy drink formulations.

All B Vitamins boost energy levels. Most energy drinks contain several of them including Vitamin B12 and niacin. Holland & Barrett Ultra KLB6 only provides one and the dose is unusually high. The recommended daily amount (RDA) for most adults is only 1.3 mg – 1.9 mg per day.

However, 50 mg is an acceptable amount. Although consuming too much Vitamin B6 can cause gastric issues, skin lesions, and other side effects, you would need to be consuming a gram or more of it per day. (https://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional/)

Even though it’s acting alone, the Vitamin B6 in Holland & Barrett Ultra KLB6 may help support low-calorie dieting by helping prevent diet-related fatigue.


​Cider Vinegar (240 mg)

Apple cider vinegar is a popular home remedy for a variety of ailments. Some people apply it topically to treat eczema and similar maladies of the skin. Others drink a spoonful a day, hoping its natural antibacterial qualities will help keep them fit and well.

Apple cider vinegar is also associated with weight loss. However, although some studies show apple cider vinegar can suppress appetite, these studies were conducted on people who drank vinegar from a spoon. A little dried vinegar extract in a capsule is unlikely to pack a similar punch.

Even when you are taking real apple cider vinegar, the level of weight loss (if any) you experience is unlikely to be dramatic.

The volunteers who took part in one study took one tablespoon of apple cider vinegar per day and achieved an average weight loss of 2.6 pounds (1.2 kg).

When the researchers doubled the dose to two tablespoons of vinegar per day, the participants lost 3.7 pounds (1.7 kg).

That’s progress but it wasn’t fast progress. The figures are not weekly or monthly. They refer to the amount of weight the volunteers lost in three months.

Even two tablespoons per day only helped the volunteers to lose slightly more than a pound each month. (https://www.tandfonline.com/doi/pdf/10.1271/bbb.90231)

With the right combination of diet and exercise, you can lose more weight than that in a week.


​Kelp (100 mg)

Kelp on the Beach, with seawater lapping against itOf the four ingredients in Holland & Barrett Ultra KLB6, kelp is the one that offers the most potential as a weight loss aid. Unfortunately, it’s unlikely to offer much benefit to the majority of people who decide to use this product with that goal in mind.

However, I need to point something out. It appears Holland & Barrett has made a mistake. Ultra KLB6 does not contain kelp. It contains bladderwrack. Lots of people confuse the two but you’d expect better from Holland & Barrett.

The label says Holland & Barrett Ultra KLB6 provides kelp. So does the nutritional information on the Holland & Barrett Ultra KLB6 sales page, but the “Additional Info” section provides conflicting ingredient information. Kelp (Laminariales) is not mentioned but bladderwrack (Fucus vesiculosus) is.

Although an error like this is annoying, it’s not a great issue in this case. Both ingredients are seaweeds that are added to diet pills because they provide iodine.

The Ultra KLB6 nutritional information and ingredient list don't tally. It appears the product contains bladderwrack, not kelp


The thyroid gland uses iodine to produce the hormones thyroxine (T4) and triiodothyronine (T3). Collectively known as the “T-hormones”, T4 and T3 help govern metabolism.

When your diet lacks sufficient iodine, your thyroid may struggle to produce enough T-hormones. This can cause your metabolism to slow down.

When metabolism is retarded in this way, you burn fewer calories. This makes it easier to gain weight and much harder to lose it.

(Further Reading: Thyroid Gland Overview at Endocrine Web)


By providing iodine, Holland & Barrett Ultra KLB6 may speed up the metabolism of people who are iodine deficient. This could help them to lose weight by rectifying an existing metabolic problem.

However, if you are not iodine deficient, supplementing your iodine levels is unlikely to offer any benefit at all.

If your iodine levels are already on the high side, getting extra iodine from a supplement could actually make your situation worse.

Overly high doses of iodine have been linked to the Wolff-Chaikoff effect. It’s a condition that suppresses T-hormone production (https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/wolff-chaikoff-effect).


​Lecithin (600 mg)

Lecithin is a dietary fat that’s present in a lot of different foods. The Lecithin in supplements is sometimes taken from sunflower seeds.

Lecithin is associated with many health benefits including lower cholesterol and improved immune function. It also provides compounds that may improve memory but it unclear why Lecithin is a key ingredient in KLB6 supplements. It’s not normally associated with weight loss and is a poor match for any product aimed at people with this goal in mind.(https://www.medicalnewstoday.com/articles/319260)

Holland and Barrett could greatly improve the metabolism-boosting ability of this product by ditching lecithin in favor of a respected fat burner such as capsicum extract or green tea.


How to Use Holland & Barrett Ultra KLB6

The usage guidelines on the Holland & Barrett website are vague. They state the dose is three caplets per day but don’t state if the caplets should be taken together or as three individual (1-caplet) servings throughout the day.

The caplets need to be taken with meals so it seems probable the dose is one capsule three times per day.


Health Considerations

If you are pregnant or nursing a child, please don’t take any kind of supplement without getting clearance from your doctor first.

If you have an existing medical condition of any kind at all, it would also be unwise to use supplements without checking with your doctor first.

Certain supplement ingredients can present interaction issues when combined with medication. It doesn’t matter if the medication has been prescribed by a doctor, a dentist, or another medical professional. If you are taking medication, don’t use it with supplements without asking a doctor first.

Areas of Special Concern About Seaweed Extracts

Seaweed absorbs minerals and nutrients from the water around it. That’s no bad thing but it can also absorb heavy metals such as lead, mercury, and cadmium.

Many people are concerned about this and avoid eating seaweed and its derivatives. Heavy metal toxins like mercury and lead can build up in the body over time.

The good news is research from the Universidad de La Laguna in the Canary Islands suggests the level of contamination in edible seaweeds is generally low. (https://pubmed.ncbi.nlm.nih.gov/28152409/)

A report by the Zhejiang Provincial Center for Disease Control and Prevention in China also suggests the level of contamination is low. (https://pubmed.ncbi.nlm.nih.gov/28152409/)

However, in both cases, the researchers point out there is a need to continually monitor the contamination level of edible seaweeds.

*Information on the Diet Pill Ninja website is not intended to be a substitute for professional medical advice.


Holland & Barrett Ultra KLB6 Customer Reviews

Holland &Barrett Ultra KLB6 Customer RatingsThe Holland & Barrett website appears to be the only place to go and read Ultra KLB6 customer reviews. It’s a biased source but the fact that it provides both good and bad comments suggests there has been no tampering with the feedback.

However, some of the reviews make it clear the customers received an incentive. That’s not great. An incentive can make some people feel duty-bound to leave a favorable review.

If you read all the reviews, it’s easy to see Holland & Barrett Ultra KLB6 is not a particularly powerful product. You may also notice some people are giving the product higher ratings than their comments warrant.

For instance, one lady states she’s not sure if the pills are working, says she does not recommend them, yet still provides a 4-star rating.

Someone else provides a 5-star rating because the pills are vegetarian and easy to swallow. That’s crazy.

Another reviewer admits she just started taking the pills and has her fingers crossed. Then… Bang! Another 5-star rating.

A few reviewers say they lost a pound or two but there are no reports of respectable weight loss.

If anything, the rating system makes this supplement seem better than it is.


Some Ultra KLB6 Customer Reviews

ULtra KLB6 customer feedback (taken from the Holland & Barrett website)


Does Ultra KLB6 Cause Side Effects?

I only found one customer review that mentions side effects. Most people appear to tolerate the product well.


Holland & Barrett Ultra KLB6 Purchasing Options

A Bottle of Holland & Barrett Ultra KLB6 Diet PillsAt the time of this review, a bottle of Holland & Barrett KLB6 cost £7.99 per bottle. There are 100 caplets per bottle so, if you are taking the recommended three caplets a day, each bottle should be good for 33 days.

Holland & Barrett Ultra KLB6 is a branded product, probably white label, that’s only available from Holland & Barrett stores and the company website.

As far as the price goes, Holland & Barrett Ultra KLB6 is a cheap diet pill to buy. Super cheap, in fact, and Holland & Barrett stores sometimes run promotions that can provide significant discounts to customers who buy two bottles instead of one.

Customers who are buying Holland & Barrett Ultra KLB6 online also have the option of purchasing via Subscribe & Save. This can entail savings as well but, unless you have previous experience with the product and believe it offers value, there seems little point in agreeing to accept future shipments of pills.



Holland & Barrett does not provide a money-back guarantee. Holland & Barrett Ultra KLB6 is cheap, so if you find it isn’t for you, you won’t be losing a big wad of cash but it will still be money down the drain.


Holland & Barrett Ultra KLB6 Review: Diet Pill Ninja Conclusion

The Diet Pill Ninja: Honorable Diet Pill ReviewsHolland & Barrett is a reputable British company that operates worldwide and has stores in many different countries. Unfortunately, Holland & Barrett Ultra KLB6 is not one of its better products.

Several customers reviews state the earlier version was better but you can tweak this formulation all you want the ingredients aren’t capable of providing the average person with a decent level of weight loss support.

If you have gained weight due to thyroid issues caused by a lack of iodine, Holland & Barrett Ultra KLB6 may help rectify the problem and help you to get back on track. But that’s about it. The formulation may boost your energy levels a little bit as well but it won’t offer much help with hunger or fat burning.

The most useful ingredient is kelp but Holland & Barrett’s new formulation provides 50 mg less than the old one. This could help explain why some customer reviews state the new version does not work as well for them as the original KLB6 diet pill did.

If their metabolisms were retarded due to lack of iodine, perhaps the original 150 mg dose provided a jump start and the lower 100 mg dose cannot. This is all hypothetical though. Most dieters are not iodine efficient. Taking a supplement like this would be barking up the wrong tree.


​Phentaslim: A Good Alternative to Holland & Barrett Ultra KLB6

Bottle Vegan-Friendly PhentaslimUnless you are certain you are iodine deficient and willing to take a gamble, it may be best to forget about Holland & Barrett Ultra KLB6 and choose a more suitable product instead. I suggest Phentaslim.

Phentaslim costs more than Holland & Barrett Ultra KLB6 but it’s a powerful product that helps you to eat less by stomping on your hunger and boosts your metabolism to help you to burn extra fat.

If you have a lot of weight to lose and want to get the best value for money, there’s a lot to be said for ordering two or three boxes instead of one.

When you buy two boxes of Phentalsim, you get an extra bottle for free.

Alternatively, you  can take advantage of the option to get five boxes for the price of three.

Even with the multi-buy savings, there’s no denying using Phentaslim is going to be more expensive than Holland & Barrett Ultra KLB6 but it’s a far superior product. Better still, the manufacturer offers free shipping and a 60-day money-back guarantee.

Buy Phentaslim 
     Read My Phentaslim Review

Ninja Sword