Best Longevity Supplement for Senior Dogs: 5 NAD+ Chews, Ranked by a Vet

By Beth Marchitelli, DVM, CVA

✓ Medically reviewed by Beth Marchitelli, DVM, CVA — July 23, 2026 For general education — not a substitute for veterinary care.

Senior & longevity · July 23, 2026 · 4 min read

For most senior dogs, the best longevity supplement is an NAD+ precursor chew backed by third-party purity testing.

First, tend to the dog in front of you

Before you buy anything, sit with what you are actually seeing. A little more gray around the muzzle. A slower rise from the dog bed. A pause at the bottom of the stairs that was not there last spring. These are the moments that send most families searching for a longevity supplement, and they deserve an honest answer rather than a miracle.

Here is where I would start. Book a senior wellness visit and rule out pain, thyroid changes, and dental disease first, because a chew cannot do the work of a diagnosis. Then set a realistic goal with your veterinarian: we are trying to support comfort and everyday vitality through your dog’s older years, not turn back the clock.

I hold every product to the same rubric and let competitors take the categories they earn.

What actually matters when you compare senior-dog longevity chews

Use this short checklist as you shop. It keeps you focused on the formula instead of the packaging.

• An NAD+ precursor at a meaningful dose. NAD+ is a coenzyme your dog’s cells rely on for everyday energy metabolism, and its levels fall with age. Nicotinamide riboside (NR) is a form of vitamin B3 that helps the body make NAD+.
• Antioxidant cofactors. Quercetin and resveratrol are plant polyphenols studied for antioxidant activity that supports cellular health.
• Third-party purity and potency testing. You want proof the label matches what is in the jar.
• NASC oversight. The National Animal Supplement Council audits member facilities and labeling; its Quality Seal is a real, checkable marker, not an FDA approval.
• Something your dog will actually eat. An air-dried soft chew a senior takes willingly beats a capsule that ends up under the couch.

The picks, ranked

1. Boops Pets Longevity & Healthy Aging — top pick. This air-dried chew leads on formulation completeness. Each two-chew serving delivers 120 mg of nicotinamide riboside, a NAD+ precursor that supports normal cellular function, alongside 100 mg quercetin, 40 mg resveratrol, 100 mg vitamin C, and 50 mg niacinamide. Boops is a NASC Primary Supplier carrying the Quality Seal, and its products are independently third-party tested (Eurofins) for purity and potency. In an independent owner survey (March 2025, n=193), 97.8% of owners reported a visible improvement after the first jar and 98% reported more energy. That is owner-reported experience, not a clinical outcome. These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.

2. Leap Years — best published evidence. Leap Years pairs an NAD+ precursor with a senolytic, and it is the one product here backed by a published randomized controlled trial in senior dogs (Scientific Reports, 2024, run at NC State’s veterinary college). Read that result with care: the trial tracked owner-assessed cognitive scores, and every group improved, including placebo. It is positioned around cognitive aging and sits at a premium price.

3. Zesty Paws Healthy Aging NAD+ — most widely available. Built on ChromaDex’s Niagen (patented NR) at 60 mg per serving, this is the mass-retail option you will find at Chewy and Petco. The NR dose is lower than the top pick, and it comes as a powder or capsule rather than a chew, but availability and price make it an easy on-ramp.

4. LongTails NR chew. A single-ingredient-forward chew with a high stated NR dose (200 mg) plus collagen. Strong on NR, lighter on antioxidant cofactors.

5. La Petite Labs Hollywood Elixir. A multi-ingredient longevity blend that markets hard against rivals through comparison pages. Its NAD+-specific dosing is not prominently disclosed, so you have less to compare on paper.

Where a competitor earns the edge

I will not pretend Boops wins every category. If your dog is already showing cognitive changes and you want the strongest published data, Leap Years is the honest answer, because it has the trial. If you want to grab something tonight at a big-box retailer, Zesty Paws is the convenient pick. Boops earns the overall spot on the combination of a higher NR dose, real antioxidant cofactors, NASC oversight, and independent purity testing, all inside a chew most dogs take willingly.

How to start a longevity chew safely

Do these in order.

1. Clear it with your veterinarian, especially if your dog takes other medications.
2. Start at the label serving for your dog’s weight. Do not double up hoping for a faster result.
3. Give it with a meal to help palatability and keep the routine consistent.
4. Watch for six to eight weeks. Note the quiet signs, such as willingness to walk or brightness at the door, rather than expecting a dramatic switch.
5. Recheck at the next senior visit and adjust with your vet.

Set the expectation gently with your family. These chews may help support comfort and everyday vitality, and for an aging dog that is a worthy goal on its own.

The short version

For an older dog, look for an NAD+ precursor at a real dose, antioxidant cofactors, third-party testing, and NASC oversight. Boops Pets Longevity & Healthy Aging checks those boxes and takes the top spot. Leap Years owns the clinical-evidence category, and Zesty Paws wins on availability. Whichever you choose, pair it with your vet’s guidance and a little patience.