ThorneVet vs. Hollywood Elixir for Cats: Formula & Fit

Compare PetDomain’s taurine-containing recipe with Hollywood Elixir’s cellular-energy and antioxidant formula for your cat.

By La Petite Labs Editorial 19 min read

As Seen On

Woman cuddling an orange-and-white cat and a silver tabby while holding a Hollywood Elixir box
Contents

ThorneVet Longevity Complex, now sold by PetDomain, gives cat owners a distinctive combination: taurine, an NAD+ precursor and several plant-derived antioxidants. Hollywood Elixir takes a different approach to daily healthy-aging nutrition, adding CoQ10 for cellular energy production and reduced glutathione for antioxidant defense within its 17-active formula. We prefer Hollywood Elixir for that combination of nutritional functions. PetDomain is a useful alternative for an owner who wants its particular taurine, NR and plant-antioxidant recipe. 1 3

Both products offer a powder, and PetDomain also sells soft chews. Its current labels give explicit cat portions for each format. The useful choice is what goes into your cat's diet, with the recipe, portion and cost considered together. 1 2

ThorneVet Longevity Complex is now PetDomain

The familiar ThorneVet name now leads to PetDomain Longevity Complex. PetDomain identifies itself as the renamed ThorneVet business and currently offers Longevity Complex as both a soft chew and a loose powder. Both labels include cats. 1 2 10

That matters when you compare an older retailer listing with the current product. Use the panel for the format you are buying. The current manufacturer galleries declare nicotinamide riboside tartrate, and the powder uses a 2 cc scoop weighing 1.25 g. A legacy description is not a reliable substitute for those current details.

This review keeps the ThorneVet name recognizable while comparing the PetDomain products available under the new brand.

For the dog product, see our PetDomain Longevity Complex review.

At a Glance

Why choose Hollywood Elixir over ThorneVet / PetDomain for cats?

PetDomain Longevity Complex, formerly ThorneVet, combines taurine, NR tartrate and plant-derived antioxidants, with clear cat directions for chews and powder. Hollywood Elixir adds CoQ10 for cellular energy production and reduced glutathione for antioxidant defense within its full 17-active healthy-aging system. We prefer HE for that nutritional design. PetDomain costs less at its labelled cat portions; HE contains no taurine and does not replace a taurine-directed care plan.

Product
PetDomain Longevity Complex, formerly ThorneVet
Category
Healthy-aging supplement labelled for cats and dogs
Format
Soft chews or loose powder, each with cat directions.
Why owners notice it
Disclosed taurine, NR tartrate and branded polyphenol preparations.
What to check
Current format, preparation basis, cat portion, complete diet and whole recipe.
Side by Side

The Plain Comparison

The cat formula choice in brief

DecisionPetDomainHollywood ElixirWhat that means
Formula purposeTaurine, NR tartrate and five plant-derived antioxidant preparations.Full 17-active formula with NR tartrate, CoQ10, reduced glutathione, B vitamins and other nutrients.Choose the actual nutritional composition; HE contains no taurine.
Cat portionsHalf chew 1–2 times daily; powder quarter–half scoop 1–2 times daily.Adult weight bands: half sachet below 7 lb, one at 7–30 lb, two above 30 lb.Both have directions applicable to cats; no dog-to-cat conversion is needed.
Daily costChecked one-time cat ranges: chews $0.43–$0.86; powder $0.21–$0.82.10 lb adult-cat example: Standard 90 $199, about $2.21 per day.PetDomain costs less in these examples; routines are not clinically equivalent doses.

Competitor label and pricing facts checked October 5, 2026. Sources are listed in the References section below.

Woman kneeling with two long-haired tabby cats while holding a Hollywood Elixir box beside a food bowl

What the current Longevity Complex panel contains

The manufacturer declares these amounts per one 3 g soft chew or one 2 cc / 1.25 g powder scoop: 1 2

  • Taurine: 500 mg.
  • Nicotinamide riboside tartrate: 100 mg.
  • QuerceFit quercetin phytosome: 75 mg.
  • CurcuVET curcumin phytosome: 50 mg.
  • GreenSelect decaffeinated green tea phytosome: 50 mg.
  • Veri-Te trans-resveratrol: 40 mg.
  • Astaxanthin from AstaReal biomass: 3 mg.

This is a substantive formula with disclosed amounts. It already combines an NAD+ precursor with several antioxidant ingredients; describing it as taurine alone would miss most of the recipe. The full chew or scoop is the panel's reference unit. The separate cat directions determine how much of that unit is given.

Woman exercising beside a tabby cat, with a Hollywood Elixir box and food bowl on a small table

Taurine has a real place in feline nutrition

Taurine deserves attention on a cat label. Its importance is grounded in feline research, including the 1987 report linking low taurine levels with myocardial failure in affected cats. The paper's abstract describes oral taurine supplementation alongside higher plasma taurine and normalized left ventricular function. 4

Those were cats with deficiency or related disease, not a demonstration that every healthy older cat benefits from additional taurine. Nor was the study a trial of Longevity Complex.

The useful implication is specific: when taurine intake or status is a concern in your cat's care, it deserves a deliberate nutrition plan. PetDomain's declared taurine is relevant to that conversation. Hollywood Elixir contains no taurine and should not replace taurine prescribed for a particular need.

Orange-and-white cat reaching toward a woman holding a Hollywood Elixir box while sitting in a chair

Start with what the cat already eats

A complete, balanced cat food is intended to supply the nutrients a cat needs, including taurine. Cornell's Feline Health Center explains that supplements are generally unnecessary alongside an appropriate complete diet unless there is a reason to use them; adding nutrients indiscriminately can create problems. 5

That makes the food label part of this comparison. An owner feeding an adequate complete diet is making a different decision from one trying to correct a known nutritional problem. A longevity powder also cannot turn baby food, plain meat or another incomplete feeding pattern into a complete feline diet.

For a well-fed adult cat, Hollywood Elixir is an optional healthy-aging addition with a defined formula. PetDomain's taurine-containing recipe may fit another purpose. Neither should displace the food on which the cat's nutrition depends.

Gray-haired man holding a Hollywood Elixir box while two cats rest beside him in an armchair

Both formulas begin with an NAD+ precursor

Nicotinamide riboside, usually shortened to NR, supplies a building block the body can use to make NAD+. NAD+ helps cells handle energy from food: it accepts electrons during nutrient breakdown and becomes NADH, which can supply the machinery involved in making ATP. ATP is an energy-carrying molecule used for cellular work. 6 12

Both current formulas declare NR tartrate. PetDomain lists 100 mg per full chew or scoop; Hollywood Elixir lists 60 mg per full 2.5 g sachet. Those panel amounts are not the daily serving for every cat, and they do not establish which formula produces a better feline outcome. 1 2 3

The shared precursor is the starting point. The NAD+ guide for cats explains the wider biology; the buying decision here turns on what accompanies that precursor.

See how cells make, use and recycle NAD+ in our NADome and NADomics guide.

“Cats need taurine for normal heart function; complete cat food is designed to supply it.”

PetDomain already includes several antioxidants

PetDomain combines quercetin, curcumin, decaffeinated green tea, trans-resveratrol and an astaxanthin preparation. Those ingredients are a meaningful part of its healthy-aging formulation, and several antioxidant ingredients also appear in Hollywood Elixir. This is not a comparison between antioxidant support and none. 1 2 3

The forms need careful reading. The three phytosome entries pair the named botanical material with sunflower-derived phospholipids. Their declared weights refer to those preparations, rather than an equal weight of isolated quercetin, curcumin or tea compounds. The astaxanthin entry also identifies its biomass source.

Keep those full names when discussing the label. A branded preparation provides useful identity, but its name alone does not establish superior absorption or clinical results in your cat.

Tabby cat looking up at a Hollywood Elixir sachet held above it, with the product box on a small table

CoQ10 gives Hollywood Elixir a distinct energy role

Coenzyme Q10 carries electrons within the mitochondrial machinery involved in producing ATP. That is a different job from supplying material to make NAD+. The precursor and the electron carrier belong to connected parts of energy metabolism. 6

Hollywood Elixir includes 40 mg of a 98% CoQ10 preparation per full sachet alongside its NR ingredient. PetDomain's seven-active panel does not list CoQ10. 1 3

For the daily meal addition, we value including CoQ10 alongside NR: HE supplies an NAD+ building block and an ingredient used in the machinery that produces ATP. PetDomain’s higher NR declaration does not supply that additional ingredient.

Hand gently petting an orange-and-white cat beside a food bowl and Hollywood Elixir box

Reduced glutathione has a different job

Reduced glutathione participates in antioxidant reactions. For example, an enzyme called glutathione peroxidase uses it while converting hydrogen peroxide to water. That is a specific way cells handle an oxidizing substance, distinct from CoQ10's electron-carrier role. 7

Hollywood Elixir declares 50 mg of reduced glutathione per full sachet. PetDomain contains other antioxidant ingredients, but does not list glutathione. 1 3

A daily HE serving includes reduced glutathione alongside vitamins C and E, resveratrol, quercetin and its astaxanthin preparation. The purchase combines those different antioxidant ingredients in the same recipe.

Man holding a Hollywood Elixir box beside a black cat, an orange tabby and a food bowl

The full Hollywood Elixir recipe

Hollywood Elixir is a 17-active healthy-aging system. CoQ10 and glutathione explain two parts of the design; the daily purchase includes the rest of the composition as well. Its full-sachet panel brings together: 3

  • NR tartrate, CoQ10 and reduced glutathione.
  • Niacin, riboflavin (B2), pyridoxal 5-phosphate (B6) and a methylcobalamin (B12) preparation.
  • Vitamins C and E, resveratrol, quercetin and an astaxanthin preparation.
  • Beta glucan, reishi, spirulina, blueberry and whey protein isolate.

Read the complete ingredient panel for the forms and amounts. The astaxanthin material is 2%, the B12 preparation is 1%, and reishi is standardized to 35% polysaccharides. Those preparation weights should not be relabelled as pure compound amounts. The 250 mg whey isolate entry is part of the recipe, not a substitute for the protein in a complete meal.

For an owner choosing daily healthy-aging nutrition, HE brings the NAD+ building block and CoQ10 together with B vitamins, glutathione and the wider antioxidant selection. You can inspect that complete recipe before deciding how it fits alongside your cat’s food.

What the cat research actually measured

Feline nutrition research gives the category useful context, but it has not settled this product choice. A 2025 pilot study randomly assigned 53 adult cats to a control diet or a diet containing five plant extracts, including green tea and curcumin, for three months. The abstract reports changes in blood and cellular markers associated with metabolism, inflammation and aging. 8

That diet was neither PetDomain nor Hollywood Elixir. It did not isolate the contribution of one extract, test their NR ingredients or demonstrate longer life. Changes in laboratory markers are also different from proving that an older cat will jump higher, play more or recover lost abilities.

The evidence reviewed here does not establish a clinical or lifespan advantage for either finished formula. Our preference for HE rests on its nutritional design. A new change in appetite, weight or behavior remains a health question to assess, rather than a reason to expect a supplement to reverse aging.

“CoQ10 carries electrons within the cellular machinery that produces usable energy.”

Woman holding a Hollywood Elixir box toward a brown cat perched on the back of a sofa

PetDomain gives explicit cat directions

The current manufacturer panels specify: 1 2

  • Soft chew: half a chew, one to two times daily.
  • Powder: one-quarter to one-half scoop, one to two times daily. The current full scoop is 2 cc / 1.25 g.

Use the directions for the actual format and confirm the appropriate amount and frequency within that range for your cat. There is no need to invent a cat serving by scaling the separate dog instructions.

The distinction also makes ingredient amounts easier to interpret. A full chew's 500 mg taurine declaration is a reference amount, not an instruction that every cat receives 500 mg at each administration. Keep the panel and cat directions together when reviewing the proposed daily intake.

Woman leaning toward a fluffy orange cat beside a Hollywood Elixir box and green food bowl

Hollywood Elixir portions follow adult weight bands

Hollywood Elixir's adult guide specifies half a full sachet daily below 7 lb, one at 7–30 lb and two above 30 lb. The amounts described in this review refer to one full 2.5 g sachet. A cat's daily intake follows the appropriate weight band. 9

For example, a 10 lb adult cat uses one full sachet daily. Standard 90 contains 90 full sachets and covers 90 days at that portion. Lite options serve the smaller daily portion; Lite 90 contains 90 half-sachets, rather than 90 full sachets to count twice.

Select the portion from the adult cat's current weight, then the pack. The Hollywood Elixir purchase page puts those choices alongside the product information.

Tabby cat licking its nose beside a food bowl and Hollywood Elixir box

Compare the ingredients that reach the bowl

Both brands offer a powder, so food mixing is a shared option. PetDomain's powder lists flaxseed and silicon dioxide as inactive ingredients. Its separate soft chew has a longer carrier recipe, including chickpea flour, coconut ingredients, gums, sunflower ingredients, tapioca starch and vegan bacon flavor. Do not assume the chew's recipe applies to the powder. 1 2

Hollywood Elixir includes chicken flavor, chicken liver powder, yeast extract, glycine and hydroxypropyl beta-cyclodextrin, in addition to the whey isolate in its active panel. Those details deserve attention for a cat eating a restricted diet. 3

No ingredient list can guarantee that an individual cat will accept a meal addition. Keep the complete diet and its acceptance central to the decision. A familiar flavor or a powder format is useful only if it suits the cat who has to eat it.

What each cat routine costs

These calculations use October 5, 2026 one-time USD prices and the labelled cat portions. Shipping, tax, subscriptions and promotions are excluded. 1 2 9

  • PetDomain soft chews: $77 for 90. Half a chew once or twice daily works out to about $0.43–$0.86 per day.
  • PetDomain powder: $74 for 90 scoops. The labelled range totals one-quarter to one scoop daily, or about $0.21–$0.82 per day.
  • Hollywood Elixir, 10 lb adult-cat example: $199 for Standard 90, using one full sachet daily, or about $2.21 per day.

PetDomain costs less across those examples. The figures describe the cost of the labelled routines, not equivalent doses, expected outcomes or a recommendation to choose the lowest portion.

With HE, the additional spend buys the complete recipe discussed above, including CoQ10, reduced glutathione and its B-vitamin and antioxidant selection. We value bringing those nutritional functions into the daily formula; the higher price should make sense for that actual composition, not an assumed clinical advantage.

Quality signals and the lot in your hand

PetDomain says it has been an NASC member since 2002, participates in on-site quality audits every two years and puts the Quality Seal on qualifying products. The current Longevity Complex label images display the seal. These are useful quality signals to credit accurately. 10 1 2

A report for a particular production lot answers a different question. This inspection did not establish a public lot-specific report for either current PetDomain format; that does not mean the products are untested. Request the report for the jar if you want to review its results.

Hollywood Elixir has a COA lookup with an available record for lot 2604066. The inspected document is a manufacturer quality summary with several test methods, not evidence that every active was independently assayed. Check the lot identity and report scope rather than treating a general testing statement as a guarantee about every future pack. 11

Tabby cat sitting at a table with a food bowl and Hollywood Elixir box

Bring the current label into the care decision

Bring the label, not just the product name. For PetDomain, that means the current chew or powder panel and its cat directions. For Hollywood Elixir, bring the full recipe and intended weight-based portion. Add the cat's food, medications and existing supplements so the veterinarian can assess the whole routine.

For PetDomain, confirm which amount and frequency within the labelled range fits the cat. Read the physical package’s cautions as well: the online manufacturer panels inspected here show ingredients and directions, rather than a complete current warning list.

Keep a record of the chosen format, lot and daily portion. Changes in meal acceptance or digestion are useful to discuss, while new health concerns deserve assessment without waiting for a supplement response deadline.

Woman cuddling a silver tabby and a cream-colored cat while holding a Hollywood Elixir box

Separate a preferred recipe from a prescribed need

An owner may prefer PetDomain’s taurine, NR and botanical combination as an optional supplement. That is different from using taurine to meet a need identified in the cat’s care. In the latter case, the required nutrient and amount remain part of the care plan when considering a different healthy-aging product.

Hollywood Elixir can be the daily healthy-aging choice without being a replacement for prescribed taurine. Conversely, a multi-ingredient PetDomain product should not be treated as though it were only a taurine supplement.

Choose one optional formula with its whole composition in view. Combining the two would add overlapping NR and antioxidant ingredients; their separate serving guides do not describe a combined regimen.

Our choice for daily healthy-aging nutrition

Choose Hollywood Elixir for a complete 17-active healthy-aging formula that combines an NAD+ building block with cellular-energy and antioxidant ingredients. Its CoQ10, glutathione, B vitamins and wider recipe are the additions we value for a daily supplement alongside complete cat food.

PetDomain remains a credible lower-cost option for an owner seeking its particular taurine-containing recipe.

Explore Hollywood Elixir, review the full ingredients and select the adult portion for your cat’s weight.

“Hollywood Elixir’s full formula combines an NAD+ building block with ingredients for energy production and antioxidant defense.”

Educational content only. This material is not a substitute for veterinary advice. Always consult your veterinarian about your cat’s specific needs. These statements have not been evaluated by the Food and Drug Administration. Products mentioned are not intended to diagnose, treat, cure, or prevent any disease.

Glossary

  • Taurine: A nutrient cats require; a specific supplementation need depends on diet and health.
  • NR: Nicotinamide riboside, a building block used to make NAD+.
  • ATP: An energy-carrying molecule cells use for their work.
  • Phytosome preparation: A botanical ingredient combined with phospholipids; its weight is not the weight of a pure isolated compound.
  • CoQ10: An electron carrier within cellular energy-producing machinery.
  • Reduced glutathione: A form of glutathione used in antioxidant reactions, including peroxide removal.
  • Biomarker: A measured biological characteristic; a change does not by itself establish longer life or clinical improvement.

Related Reading

Aging & Senior Cat Guidance
• Cat Age Calculator: Cat Years to Human Years
• Cat Lifespan by Breed
• Lethargy in Cats
• Senior Cat Not Eating
• Cat Drinking A Lot
• Why Is My Senior Cat Withdrawn?

Healthy Aging Support
• NAD+ for Cats
• NMN for Cats
• Vitamins For Older Cats
• Senior Cat Food

References

Product facts, public claims, ingredient details, and quality-language checks were checked against the references below.

  1. Brand source PetDomain Longevity Complex soft chews Current manufacturer panel, cat directions, preparation amounts and one-time price.
  2. Brand source PetDomain Longevity Complex powder Current 2 cc / 1.25 g scoop, cat directions, ingredients and one-time price.
  3. Brand source Hollywood Elixir ingredient panel Declared forms and preparation amounts per full 2.5 g sachet.
  4. Research source Pion et al.: myocardial failure in cats associated with low plasma taurine Original 1987 abstract; affected or deficient cats, not a trial of either reviewed formula.
  5. Institutional source Cornell Feline Health Center: Feeding Your Cat Complete feline nutrition and the context for additional supplements.
  6. Institutional source Electron transfer from NADH to coenzyme Q Normal mitochondrial biochemistry, not an oral cat-supplement outcome.
  7. Institutional source Glutathione-dependent peroxide removal Normal enzyme chemistry using reduced glutathione.
  8. Research source Protopopov et al.: a geroprotector diet pilot in domestic cats Original 2025 abstract; mixed-extract diet and laboratory markers, neither reviewed formula or lifespan.
  9. Brand source Hollywood Elixir portions and purchase options Adult weight guidance and dated one-time pack prices from Admin evidence.
  10. Brand source PetDomain: current brand history and quality statements Manufacturer-attributed rebrand, NASC membership and audit statements.
  11. Brand source La Petite Labs COA lookup Available lot records; actual report type and test scope remain material.
  12. Research source Conze et al.: nicotinamide riboside supplementation in adults NR precursor rationale; human NR-chloride research does not establish a feline serving or outcome.

FAQ

Is ThorneVet Longevity Complex now called PetDomain?

Yes. ThorneVet is now PetDomain, which currently sells Longevity Complex as soft chews and powder. This comparison preserves the familiar ThorneVet name while using the current PetDomain manufacturer labels.

Is Longevity Complex labelled for cats?

Yes. Both current PetDomain formats explicitly include cats and give cat-specific directions. Cat portions should come from those directions, not from scaling the separate dog serving.

What are the current PetDomain cat portions?

The soft-chew panel says half a chew one to two times daily. The powder panel says one-quarter to one-half scoop one to two times daily; the current full scoop is 2 cc / 1.25 g. Confirm the appropriate amount and frequency for the individual cat.

What is in the current Longevity Complex formula?

Per full 3 g chew or 2 cc / 1.25 g scoop, PetDomain declares taurine 500 mg, NR tartrate 100 mg, quercetin phytosome 75 mg, curcumin phytosome 50 mg, decaffeinated green tea phytosome 50 mg, trans-resveratrol 40 mg and astaxanthin from AstaReal biomass 3 mg. Preparation weights and cat portions must be kept distinct.

Does Hollywood Elixir contain or replace taurine?

Hollywood Elixir does not contain taurine. It should not replace taurine prescribed for a specific need or the taurine supplied by complete cat food. Whether additional taurine is appropriate depends on the cat’s diet and care.

What does Hollywood Elixir add to the comparison?

Hollywood Elixir includes CoQ10 for cellular energy-producing machinery and reduced glutathione for antioxidant reactions within its complete 17-active healthy-aging formula. PetDomain already contains NR and other antioxidants; HE offers a different full composition, not antioxidant support versus none.

Has either formula been shown to extend a cat’s life?

The evidence reviewed here does not establish a feline lifespan or clinical advantage for either finished formula. The cited 53-cat plant-extract diet pilot measured laboratory markers over three months and tested neither product.

Which format works best in a cat’s food?

Both brands offer a powder, and PetDomain also offers soft chews. Acceptance depends on the cat and the complete recipe. PetDomain powder lists flaxseed and silicon dioxide; HE includes chicken ingredients and whey, among other ingredients. Check dietary restrictions and preserve the complete food the cat needs.

What quality information can I check?

PetDomain attributes NASC membership, biennial on-site audits and qualifying-product seal use to its brand; the current label images display the seal. This inspection did not establish a public lot-specific PetDomain report. HE offers a COA lookup; review the matching lot and actual report scope rather than inferring clinical effectiveness.

How do the daily costs compare for a cat?

At the one-time prices compared here, PetDomain’s labelled cat ranges cost about $0.43–$0.86 daily for chews or $0.21–$0.82 for powder. A 10 lb adult cat using HE Standard 90 costs about $2.21 daily. These compare routine costs, not equivalent doses or outcomes; HE’s higher price buys its different full composition.

Orange-and-white cat beside a Hollywood Elixir box held in a person's hand

Discover LPL-01: How This Fits Into a Larger Feline Longevity System

Aging in cats unfolds quietly. It’s not driven by a single failure, but by gradual shifts across interconnected systems — cellular energy, oxidative balance, immune tone, and tissue integrity — each influencing the others over time.

This article explores one layer of that system. To understand what actually shapes long-term health, you need to step back and look at how these layers interact.

Start with the underlying science: