If you are comparing MobiFlex for a stiff or ageing dog or cat, the question that matters most is a simple one: what is actually in the scoop you are paying for?
Both products are South African and registered under Act 36/1947, and both come in a 250g tub with a 5g serving, so a like-for-like comparison is straightforward. Everything below comes from each manufacturer’s own published label.
The short answer
NutriFlex Advanced delivers a full 5g of active ingredients in every 5g scoop. MobiFlex lists roughly 1.8g per 5g scoop, which leaves over half of each serving (about 3.2g) unaccounted for on the label.*
Because that carrier base is not disclosed, you cannot confirm whether it contains sugar-based carriers such as maltodextrin or dextrose. For diabetic pets, or pets that need tighter carbohydrate control, that is a real gap in the information.
NutriFlex® also includes two joint-support ingredients MobiFlex does not list: type II collagen, the primary structural protein of joint cartilage, and hyaluronic acid, the lubricant in synovial joint fluid.
If you want the most active formula per rand with full ingredient disclosure, NutriFlex® Advanced is the stronger choice. MobiFlex may suit pets that specifically need glucosamine and green-lipped mussel, provided you are comfortable with a large undisclosed carrier base and a formula without listed type II collagen or hyaluronic acid.
*Based on the active ingredients listed on the product label and MobiFlex® product page (Kyron Labs, accessed June 2026), a 5g serving discloses 1,835mg of active ingredients, leaving 3,165mg (63.3%) as undisclosed carrier base.
Side by side: what is in 5g
Figures from each brand’s published label. MobiFlex also lists a total sulphur value of 205mg, a measured parameter rather than a separately added ingredient, so it is not counted again in the total of active ingredients. Check the current pack, as formulations can change.
|
PER 5G SCOOP |
NUTRIFLEX® ADVANCED |
KYRON MOBIFLEX® |
|
Hydrolysed Collagen Type I and III |
✓ 3,300 mg |
✗ none |
|
Hydrolysed Collagen Type II (with chondroitin, GAGs, proteoglycans, hyaluronic acid) |
✓ 1,000 mg |
✗ none |
|
Protein (source of amino acids) |
✓ ~80% collagen protein |
✗ not disclosed |
|
Hyaluronic acid |
✓ natural extraction |
✗ none |
|
Chondroitin sulphate |
✓ natural extraction |
✓ 600 mg |
|
MSM |
✓ 500 mg (OptiMSM®) |
✓ 500 mg |
|
Vitamin C |
✓ 200 mg (calcium ascorbate) |
✓ 30 mg (ascorbic acid) |
|
Glucosamine hydrochloride |
✗ none |
✓ 500 mg |
|
Green-lipped mussel powder |
✗ none |
✓ 200 mg |
|
Manganese |
✗ none |
✓ 5 mg |
| Source of core joint actives | ✓ natural extraction |
isolated compounds, manufactured separately |
|
TOTAL declared active ingredients |
5,000 mg (100%) |
approx. 1,835 mg (~37%) |
|
Undisclosed ingredients |
✓ none (0%) |
✗ undisclosed carrier base (~63%) |
|
Added sugar (maltodextrin, dextrose) |
✓ none |
not disclosed |
|
Suitable for diabetic pets (sugar-free) |
✓ yes |
✗ not confirmed |
|
Allergens |
✓ none |
shellfish |
|
Human food-grade certified |
✓ FSA Accreditation |
✗ not stated |
|
SA registration (Act 36/1947) |
V31175 |
V17705 |
|
Pack size |
250g |
250g |
Download the NutriFlex® vs MobiFlex ingredient comparison (PDF)
The scoop test: how much of it is actually active?
A joint supplement can only work through the active ingredients your pet actually swallows. The rest is excipients and bulking agents your pet does not need.
NutriFlex Advanced is 100% functional ingredients. Every gram in the tub is collagen (types I, II and III), MSM or vitamin C. MobiFlex’s own label adds up to roughly 1.8g of declared functional ingredients per 5g scoop, and the label does not break down the remaining 3g or so of carrier base.
Keep that in mind when you compare prices. Cost per tub tells you very little. Cost per gram of functional ingredients tells you what you are actually buying, and on that measure a 100% active formula comfortably beats one where only about a third of each scoop is declared active.
The real gap: cartilage structure and joint lubrication
Type II collagen is the main structural protein in joint cartilage. It gives cartilage its tensile strength and resilience. NutriFlex Advanced is built around a patented extraction of type II collagen from chicken sternum, which naturally contains chondroitin, glycosaminoglycans, antioxidant proteoglycans and hyaluronic acid in a single absorbable matrix. MobiFlex follows the traditional glucosamine and chondroitin model, supported by green-lipped mussel.
Hyaluronic acid deserves its own mention. It is a major component of synovial fluid, which lets the joint move without friction. NutriFlex® Advanced includes it. MobiFlex does not list it.
Glucosamine and chondroitin are established joint nutrients, and MobiFlex provides them. NutriFlex® covers the same chondroitin and GAG ground through its collagen matrix, then adds the structural collagen protein and the joint lubricant on top.
Collagen matrix vs isolated actives
MobiFlex uses a traditional joint-support model: separately added glucosamine hydrochloride, chondroitin sulphate, MSM, green-lipped mussel, manganese and vitamin C, blended into the finished powder. Glucosamine is commonly produced from shellfish chitin or fermentation, while chondroitin sulphate is typically extracted and purified from animal cartilage.
NutriFlex Advanced takes a different route. Its type II collagen comes from chicken sternal cartilage, a natural source that carries chondroitin, glycosaminoglycans, proteoglycans and hyaluronic acid within the same matrix. They arrive together as one cartilage-derived functional ingredient, not as separate isolated actives added one by one.
Shellfish and allergens
MobiFlex contains green-lipped mussel powder, a marine shellfish derivative. For most pets that is fine. For a pet with a shellfish or marine protein sensitivity, it is not.
NutriFlex® Advanced is shellfish free. The collagen comes from bovine and chicken sternum sources, and the formula carries no marine derivatives, no added sugar and no artificial flavours. It is a certified human-grade supplement, which means the finished product would pass for human consumption.
More than just joints: why collagen earns its place
Ageing pets rarely have one problem in isolation. Stiff joints tend to arrive alongside weaker muscle tone, a duller coat and slower recovery. Because NutriFlex Advanced is built on hydrolysed collagen, it is also a substantial protein source, around 90%, supplying 18 amino acids that feed skin, coat, lean muscle and gut lining as well as joints. A glucosamine and chondroitin powder does not offer that whole-body support. If your pet is older, recovering from surgery or losing condition alongside the stiffness, the collagen base is doing extra work in the same scoop.
Do not compare tubs. Compare active grams
A familiar-looking tub becomes poor value when most of the scoop is not declared active. The fair comparison is price per gram of active joint-supporting ingredients, not price per 250g tub.
Because NutriFlex® Advanced is 100% active, a 250g tub holds a full 250g of active ingredients. A formula that is about 37% active holds roughly 90g in the same size tub, with the balance made up of undisclosed carrier material. Same tub, nearly three times the working ingredients. So compare joint supplements on cost per gram of declared actives, the part that actually benefits your pet.
Which should you choose?
Choose NutriFlex® Advanced for maximum active ingredients per scoop, type II collagen and hyaluronic acid, a fully disclosed shellfish-free formula with no fillers or added sugar, and a protein base that supports skin, coat and muscle as well as joints.
Choose MobiFlex if your vet has specifically recommended a glucosamine and green-lipped mussel formula, your pet has no shellfish sensitivity, and you are comfortable not knowing what makes up most of each scoop.
Choose NutriFlex® Advanced: 100% Active Hip and Joint Formula with longevity benefits
Frequently asked questions
Is NutriFlex a good alternative to MobiFlex?
Yes. NutriFlex® Advanced targets the same joint stiffness and mobility issues, with a fuller formula. It delivers 5g of active ingredients per scoop compared to MobiFlex’s roughly 1.8g and adds type II collagen and hyaluronic acid, which MobiFlex does not list.
What are the ingredients in Kyron MobiFlex?
Per 5g, MobiFlex (made by Kyron Laboratories) lists glucosamine hydrochloride 500mg, chondroitin sulphate 600mg, MSM 500mg, green-lipped mussel powder 200mg, manganese 5mg and vitamin C 30mg, plus a total sulphur value of 205mg. The remainder of the 5g scoop is an undisclosed carrier base.
Does this comparison cover MobiFlex tablets and MobiFlex-LD?
This comparison is for MobiFlex powder for cats and dogs (V17705), the standard 5g formula. Kyron also makes MobiFlex Tablets (V24112) and MobiFlex-LD for large dogs over 50kg (V20146), and the formulas differ. Each film-coated tablet contains glucosamine 200mg, chondroitin 100mg, MSM 100mg, green-lipped mussel 450mg, manganese 10mg and vitamin C 20mg. MobiFlex-LD provides glucosamine 1.3g, chondroitin 500mg, MSM 1g, green-lipped mussel 200mg, manganese 5mg and vitamin C 33mg per 5g, so it is more concentrated than the standard powder, though it still carries an undisclosed carrier base and green-lipped mussel. NutriFlex® Advanced stays 100% active and shellfish-free.
Does MobiFlex have side effects?
MobiFlex is generally well-tolerated. The ingredient-level points to check are the green-lipped mussel powder, a shellfish derivative that pets with marine allergies should avoid, an undisclosed carrier base whose sugar content is not stated and the mild digestive upset glucosamine and chondroitin can cause in some animals when first introduced, usually settled by giving it with food. For a specific concern, consult your vet.
Does NutriFlex contain glucosamine?
NutriFlex Advanced delivers chondroitin, glycosaminoglycans and proteoglycans through its natural type II collagen matrix rather than as added glucosamine hydrochloride. These are the cartilage-supporting nutrients glucosamine is taken for, in a highly bioavailable form.
Does MobiFlex contain shellfish?
Yes. MobiFlex contains green-lipped mussel powder, a marine shellfish derivative. NutriFlex® Advanced is shellfish-free and uses bovine and chicken sternum collagen sources.
Can I switch my pet from MobiFlex to NutriFlex®?
Yes. Both are daily 5g powders mixed into food. Match the scoop to your pet’s weight per the NutriFlex® feeding guide and transition over a few days alongside food.
Is NutriFlex safe for cats?
Yes. NutriFlex Advanced and Maintenance joint supplements are formulated for dogs and cats of all ages from eight weeks, in weight-based servings.
This comparison is based on publicly available product information and manufacturer-published label figures at the time of writing and is provided for informational purposes. It is not veterinary advice. Formulations, labels and registrations can change, so pet owners should check the current pack or consult their veterinarian before purchase. NutriFlex® is a Smartpack Pty Ltd brand. MobiFlex® is a registered product of Kyron Laboratories and is named here for comparison only.
Sources
-
- MobiFlex® active ingredient list — kyronlabs.co.za/product/mobiflex/ (accessed June 2026). Disclosed per 5g: Glucosamine HCl 500mg, Chondroitin Sulphate 600mg, MSM 500mg, GlycOmega Plus 200mg, Manganese 5mg, Ascorbic Acid 30mg = 1,835mg total active.
- NutriFlex Advanced product label — nutriflex.co.za 5g scoop = 5,000mg 100% active, fully disclosed.