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Amino Acid Supplements

Amino Acids are the structural units that make up protein. Proteins are essential nutrients for the human body. They are the building blocks of the body and also serve as a fuel source. Amino acid supplements are increasing in popularity amongst athletes, bodybuilders and others on calorie-controlled diets.

All Amino Acid Supplements

SAVE
10%
Buy 5-HTP 100mg
5-HTP 100mg VV
9.4 / 10
487 reviews
from £12.95
£11.66
  • Naturally sourced - 99% pure 5-HTP
  • Top selling supplement
  • Well researched nutrient
  • Good alternative to St John's Wort
Buy L-Arginine 1000mg
L-Arginine 1000mg VV
9.4 / 10
230 reviews
from
£11.45
  • Very popular amongst sports people
  • Used by the body to make nitric oxide
  • Helps relax blood vessels
  • Acts as a powerful vasodilator
SAVE
10%
Buy L-Theanine 200mg
L-Theanine 200mg VV
9.6 / 10
163 reviews
from £12.95
£11.66
  • Pure, strong and high grade material
  • Found predominantly in tea
  • Not known to be addictive
  • Fully vegetarian capsule
Buy Marine Collagen 400mg
Marine Collagen 400mg P
9.6 / 10
124 reviews
from
£10.95
  • The finest marine-sourced collagen
  • Contributes to skin elasticity
  • A guaranteed Amino Acid profile
  • Hydrolysed for easier absorption
Buy L-Lysine 500mg
L-Lysine 500mg VV
9.6 / 10
46 reviews
from
£7.49
  • Cannot be made by the body
  • An essential amino acid
Buy High Strength L-Theanine 400mg
High Strength L-Theanine 400mg VV
9.6 / 10
48 reviews
from
£9.95
  • Double-strength capsules
  • Purest form available
  • Strongest form available in the UK
  • Increases brain alpha waves
Buy L-Carnitine 500mg
L-Carnitine 500mg V
9.4 / 10
12 reviews
from
£10.95
  • High quality Amino Acid
  • Energy release
  • Bioavailable N-Acetyl form
  • A popular sports supplement
Buy L-Carnitine 1000mg
L-Carnitine 1000mg V
10.0 / 10
8 reviews
from
£9.95
  • High strength 1000mg tablet
  • A popular sports supplement
  • Aids in metabolising food into energy
  • Bioavailable N-Acetyl form

Not sure which Amino Acid Supplements to choose? Read our latest customer reviews:

The views expressed below are the personal opinion of Just Vitamins customers. Just Vitamins does not endorse these views, nor should they be regarded as health claims or medical advice. All reviews are collected and verified as genuine by a 3rd party called Feefo.

Product Name
Posted
Rating
Comment
L-Arginine 1000mg
20 Aug 2018
Service Rating: This is my first purchase from JustVitamins. Great product, value for money and speed delivery. I will be trying other products from this company
Product: Great product, it definitely works
L-Arginine 1000mg
20 Aug 2018
Great service
L-Arginine 1000mg
19 Aug 2018
Service Rating: Price, quality and delivery are generally good. However, they are often 'Out of Stock' for long periods on some items which requires my sourcing from elsewhere ... not good for them as I prefer to order everything from one place!
Product: Very effective ... but I need it with the same dosage in L-Carnitine 1000mg which is too often 'Out of Stock'. They do have L-Carnitine 500mg but this works out at twice the price... so leads me to source elsewhere!
High Strength L-Theanine 400mg
18 Aug 2018
Service Rating: Fast delivery, great prices.
Product: L-theanine is subtle but very effective. I have found that it's great for a) a calm focus, b) reducing stress and c) helping you achieve a deep long sleep without any drowsiness in the morning.
5-HTP 100mg
14 Aug 2018
Service Rating: I have been purchasing supplements from Just Vitamins for many years now and I am very impressed with their service.
Always quick and efficient and high quality goods.
I do recommend them to people whenever I can.
Product: Used these for years. They help me greatly with my anxiety problems.
Marine Collagen 400mg
13 Aug 2018
Quick and efficient
5-HTP 100mg
09 Aug 2018
Service Rating: Prompt delivery and very easy to order from. Thanks!
Product: Very happy with my purchase. Will order again
L-Arginine 1000mg
06 Aug 2018
Service Rating: The website is user friendly, the ordering process simple, the information on the products is good. Delivery was quick, packaging good.

Been on the pills now for a couple of weeks but have noticed no discernible change which is a little disappointing
Product: Taking this with Pycnogenol which combined is reportedly a cure or helps alleviates symptoms of Erectile Dysfunction. Been taking for two weeks with no discernible difference. So very disappointed at this stage but will complete the 90 day programme
High Strength L-Theanine 400mg
04 Aug 2018
Service Rating: Quick delivery good website cheap prices.
Product: Why three stars because the vitamens placed in plastic bag instead of can or box so when i picked it from my mail box it was very warm.
Marine Collagen 400mg
02 Aug 2018
Service Rating: I love just vitamins, they are a good price and quick delivery, and my favorite bit is they are in a seal pack so can be posted. I've used them 3 times so far and will continue to.
Product: I love the collagen tablets, they make my skin soft and wrinkle free, I take 2 a day so the 90 tablet pack lasts a good while.
Marine Collagen 400mg
02 Aug 2018
Service Rating: Been dealing with Just Vitamins for couple of years and have found them to be the best quality, price and fast delivery.
Product: Great price n quality, wouldn't use any other
5-HTP 100mg
02 Aug 2018
Good
Marine Collagen 400mg
01 Aug 2018
excellent
thank you
5-HTP 100mg
01 Aug 2018
Service Rating: the service was perfect on the two occasions i have used just vitamins for 5-htp,
value for money is also ok from a source i can trust.
Product: this product works well for me as it does not aggravate my tinnitus.
High Strength L-Theanine 400mg
01 Aug 2018
Very quick service. Great vitamins
L-Arginine 1000mg
01 Aug 2018
Very efficient and good service. Received products right on time. Quality very good.
High Strength L-Theanine 400mg
01 Aug 2018
Service Rating: Very fast delivery and good communication
Product: Good but not massive results.
High Strength L-Theanine 400mg
01 Aug 2018
Ordering has been a bit confusing but delivery has been good.
I hope that the quality is good , no way of knowing that.
High Strength L-Theanine 400mg
01 Aug 2018
Service Rating: Very prompt service
Product: Helps reduce anxiety quickly
L-Theanine 200mg
01 Aug 2018
Service Rating: I always buy my vitamins from here.
Great products.
Product: Can’t do without it!
Amazing for my wellbeing.
We promise slick and speedy, same-day dispatch (Mon-Fri) on all orders received by 1pm!
Most of our products are delivered in super-slim pouches that slip neatly through your letterbox!

Free delivery throughout the UK

No minimum order needed - UK Standard delivery is free.

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