The raw ingredients in Z-Stack

Vitamin C has been shown to play a complex, protective role against toxic compounds formed from oxidized lipids and may support overall immune health.

Quercetin supports a healthy inflammatory response and functions as a zinc ionophore, helping shuttle zinc into cells so your body can better absorb and utilize it.

Vitamin D3 has been shown to increase intestinal calcium and phosphate absorption, helping maintain strong bones.

Zinc is a nutrient found throughout your body that may support your immune system and metabolic function.

What This Bundle Delivers

  • Clinically Dosed to strengthen immune defense
  • Boosts nutrient absorption where it matters most
  • Improves sleep quality without melatonin
  • Supports overnight recovery + immune reset
  • Day + night system for full-spectrum support
Man sleeping Man sleeping

Why it Works

Your immune system runs 24/7.

Z-Stack® supports daily immune defense – so your body stays ready.

Z-Night™ helps your body enter deep, restorative sleep – when recovery happens, and immunity is built.

Better Sleep = Stronger Recovery = Boosted Immunity

Questions Customers Ask Most

Z-Stack® is an all-in-one immune support formula designed to provide key nutrients your body relies on for daily immune defense. Each serving combines vitamin C, vitamin D3, zinc, and quercetin, ingredients selected to work together to support immune function, antioxidant protection, and healthy cellular activity.

Unlike many standard vitamin blends, Z-Stack® was developed from the research and clinical insights of Dr. Vladimir “Zev” Zelenko. Each component was carefully selected to work synergistically, helping support immune function and overall wellness in a single, convenient daily formula.

The ingredients in Z-Stack® are designed to work synergistically. Quercetin acts as a zinc ionophore, helping transport zinc into cells, while vitamins C and D3 support immune response and antioxidant protection—helping your body maintain strong natural defenses.

Z-Stack® is typically taken once daily as a two-capsule serving, making it a convenient way to support immune health with multiple nutrients in one formula rather than taking separate supplements.

Z-Night™ is a nighttime supplement designed to support restful, high-quality sleep and help your body unwind at the end of the day. It works by promoting relaxation and supporting your natural sleep cycle, so you can fall asleep more easily and wake up feeling refreshed.

Z-Night™ is formulated to support sleep without relying on harsh or habit-forming ingredients. Instead, it focuses on helping your body relax naturally and maintain a healthy sleep rhythm, making it ideal for consistent nightly use.

Z-Night™ is designed to support restful sleep while helping you wake up feeling clear and refreshed, not sluggish. It works with your body’s natural rhythms rather than overpowering them.

Z-Night™ is ideal for individuals who have trouble winding down at night, experience occasional restless sleep, or want to improve overall sleep quality as part of a healthy routine.

Lady on a laptop in a white kitchen Lady on a laptop in a white kitchen
Zelenko Subscriber Rewards

Stay Consistent. Earn Rewards.

Subscribe to your favorite products and enjoy automatic deliveries, exclusive subscriber savings, 10% back in store credits, and more!

Discover Our Wellness Bundles


Trusted Wellness, Real Feedback

"I have been on these two wonderful products for about 2–3 years now. They have kept both me and my husband in tip-top immune shape. I've also tried many of their other products, and they work well. The company and its service are unbeatable for customer support. You can't go wrong with any of their products. I'm very thankful that God blessed us with Dr. Zelenko."

Susan C. 🇺🇸

"It’s wonderful getting Z-Sleep free with my Z-Stack! I’m getting in a groove for sleeping now!"

Eileen A. 🇺🇸

"I love these products!! Please don’t change!! I have been receiving them delivered to my home monthly for a long time now!! I love the quality and I hope Dr. Z is smiling down on a job well done by continuing his legacy!!"

Jonnie B. 🇺🇸