Lean Stack across Europe

The Lean Stack pairs our TIRZEPATIDE 60 pen, in stock and shipping now, with our NAD+ 1000 pen. It groups the most thoroughly trialled compound we sell with one whose human evidence is modest and mostly indirect, and we would rather say so than let the pairing imply equal footing. You are typically looking at this set from the weight-loss goal.

Tirzepatide: a dual agonist with two completed Phase 3 programmes

Tirzepatide activates both the GIP and the GLP-1 receptor. Earlier compounds in the class, semaglutide among them, act on GLP-1 alone; the added GIP activity is what defines it (what is tirzepatide?). It has completed Phase 3 programmes in two indications: SURMOUNT in obesity and SURPASS in type 2 diabetes. That two-indication record is unusual for anything on this site, and it is the reason tirzepatide holds a marketing authorisation while most of our range does not.

What SURMOUNT-1 reported

The 72-week SURMOUNT-1 trial (NCT04184622) studied 5 mg, 10 mg and 15 mg once weekly against placebo in 2,539 adults. Mean change in body weight at week 72 was −15.0% at 5 mg, −19.5% at 10 mg and −20.9% at 15 mg, against −3.1% for placebo (Jastreboff AM et al. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med 2022. PMID 35658024). Longer follow-up in people with obesity and prediabetes reported sustained weight reduction over three years and a markedly lower rate of progression to type 2 diabetes than placebo (Jastreboff AM et al. Tirzepatide for Obesity Treatment and Diabetes Prevention. N Engl J Med 2025. PMID 39536238).

Those are group means from a supervised trial with slow upward titration and a lifestyle programme alongside the drug; they are not a forecast for you. Gastrointestinal effects, chiefly nausea, diarrhoea, vomiting and constipation, were the characteristic adverse events and were dose-related, which is why the trials escalated the dose over months rather than starting at the target. We do not publish a dosing schedule; the trial regimens are in the papers above.

This pen is not Mounjaro

Tirzepatide is authorised in the EU as the medicine Mounjaro (European Medicines Agency. Mounjaro EPAR.). That product is a specific formulation at specific strengths, dispensed by pharmacies against a prescription, with an approved dose, a summary of product characteristics and post-marketing surveillance. Our pen contains the same active compound, 60 mg in 3 ml, independently tested per batch for identity, purity and sterility. It is not that product and does not come with any of the safeguards that surround it. The trial results above describe the molecule; they do not describe this supply route. We set out the distinction in full at why these compounds are not EMA-authorised.

NAD+: a coenzyme, with a thinner and mostly indirect evidence base

NAD+ is not a peptide. Nicotinamide adenine dinucleotide is a coenzyme in cellular energy metabolism, taking part in redox reactions rather than binding a receptor (what is NAD+?). Its human trial literature is mostly about the oral precursors NMN and nicotinamide riboside rather than NAD+ itself, because NAD+ is comparatively large and poorly absorbed by mouth.

The precursor trials are clear on one point and equivocal on another. Supplementation raises blood NAD+: a long-term randomised, placebo-controlled trial of nicotinamide riboside chloride addressed safety and metabolism over an extended period (Conze D et al. Safety and Metabolism of Long-term Administration of NIAGEN (Nicotinamide Riboside Chloride) in a Randomized, Double-Blind, Placebo-controlled Clinical Trial of Healthy Overweight Adults. Sci Rep 2019. PMID 31278280), and a dose-dependent NMN trial in healthy middle-aged adults reported the same (Yi L et al. The efficacy and safety of β-nicotinamide mononucleotide supplementation in healthy middle-aged adults. GeroScience 2023. PMID 36482258). Whether that translates into a clinical outcome is less settled: a meta-analysis of NMN randomised trials found no significant benefit on fasting glucose, fasting insulin, glycated haemoglobin or lipid profile across 250–2,000 mg per day (Chen F et al. Effects of Nicotinamide Mononucleotide on Glucose and Lipid Metabolism in Adults. Curr Diab Rep 2024. PMID 39531138). The biomarker moves reliably; the downstream outcomes are inconsistent by endpoint. NAD+ holds no marketing authorisation for this use anywhere.

Where the evidence for the pair stops

No published trial has tested tirzepatide and NAD+ together. The two compounds sit at opposite ends of the evidence spectrum on this site, and putting them in one order does not transfer the strength of the tirzepatide record to NAD+. Nothing in this set is mixed or co-formulated: each pen is the same product you can buy on its own page, and we do not suggest how to sequence or combine them.

	Tirzepatide	NAD+
Molecule	Dual GIP/GLP-1 agonist peptide	Coenzyme, not a peptide
Strongest human evidence	Completed Phase 3 (SURMOUNT, SURPASS)	Trials of oral precursors; metabolic endpoints mixed
Authorised medicine exists?	Yes (Mounjaro); our pen is not it	No

Who typically chooses the Lean Stack

You usually have the weight-loss goal in view, want the incretin pen with the deepest published record, and want NAD+ alongside it for its own reasons rather than as a booster for the first pen. If you are weighing tirzepatide against the triple agonist retatrutide, the Advanced Lean Stack swaps in RETATRUTIDE 32, a compound with Phase 2 data and no authorisation anywhere; the retatrutide vs tirzepatide comparison sets the two out side by side. Either set ships from our Czech dispatch point in cold-chain packaging, with each batch certificate reachable from the QR code on the pen and published at /coa.