Begin with the purchase you would actually make
I would not start this comparison with a contest over which product raises NAD the most. A home injection service and a capsule subscription ask you to make different decisions. One includes a clinical relationship and a dispensed preparation; the other is a retail supplement purchase. The amount on a label does not make the two offers equivalent, and neither format earns a health-benefit claim simply because it appears closer to the molecule itself.
A useful first question is more ordinary: what am I trying to change, and what evidence would count as an answer? Better afternoon energy, improved walking ability and longer life are separate propositions. Write one down before opening a checkout. Otherwise, a convenient routine can become a substitute for a clear reason to buy. Our ingredient guide explains the vocabulary; this comparison concerns the decision that comes next.
The human evidence starts in different places
Martens and colleagues tested oral NR in a placebo-controlled crossover study with six-week treatment periods. Twenty-four people completed both periods, and NAD metabolism changed during NR treatment. That gives a specific oral ingredient a human biochemical evidence base. It does not compare a capsule with a home NAD+ injection. [1]
The 2019 Grant infusion pilot studied eight NAD+ recipients and three saline controls, with a six-hour infusion and sampling through eight hours. Its subject was the fate of NAD+ and related metabolites. The design did not establish a durable advantage in everyday energy or longevity. Reading those two studies together therefore leaves a route comparison open; it does not crown a winner. [2]
NMN adds a third ingredient, rather than resolving the first two. Yoshino and colleagues found improved muscle insulin sensitivity in a small, ten-week study of postmenopausal women with prediabetes. That selected population and endpoint belong with the finding. They cannot be attached to every product offered under the NAD umbrella. [3]
What the illustrative studies actually compared
| Study ingredient | What was examined | What remains open |
|---|---|---|
| Oral NR | NAD metabolism in a placebo-controlled crossover study. [1] | A direct comparison with a home injection service. |
| Oral NMN | Muscle insulin sensitivity in selected women with prediabetes. [3] | Transfer to other populations, routes and commercial products. |
| Infused NAD+ | Short-term plasma and urine metabolites in a small pilot. [2] | Durable fatigue or longevity benefit. |
Four decisions, in the right order
- Your questionName the outcome you want to understand.
- The evidenceMatch ingredient, route and outcome to a human study.
- The serviceIdentify what happens before and after the purchase.
- The commitmentCompare the full charge and renewal conditions.
The clinical service is part of the injection offer
For an injection provider, I would want the evaluation, pharmacy fulfillment and follow-up contact described separately. A polished intake form is useful only if you know who can answer a medical question after delivery. Put the clinician contact in one column and the billing contact in another. That simple distinction prevents an unanswered support ticket from being mistaken for ongoing clinical care.
Ask what the provider needs before approving treatment, which pharmacy would dispense the selected preparation and how to report a problem with a shipment. Compounded medications are not FDA-approved; the agency does not review their safety, effectiveness or quality before marketing. That is a reason to evaluate the actual service and preparation carefully rather than treating a prescription as product approval. [4]
The CoreAge Rx review focuses on consultation and cancellation boundaries. The AgelessRx review focuses on choosing among formats and reconciling price labels. Those are useful provider differences. They do not demonstrate that either service delivers a stronger biological effect.
Capsule simplicity is useful, but it has limits
A capsule purchase avoids appointments and injection logistics. That convenience can be a legitimate preference without becoming a scientific claim. I would compare the exact ingredient, serving size, capsule count, other active ingredients and order frequency. A product with several ingredients should be evaluated as a combination, not described as if a single-ingredient study tested the finished bottle.
For example, the Tru Niagen review separates its NR label from bottle-size and subscription choices. The Renue By Science review addresses a different ingredient and delivery claim. A larger bottle or a more elaborate formulation might fit someone’s preferences, but neither change answers whether the person will experience a meaningful benefit.
Keep quality and effectiveness on separate lines. A product can have a clearly stated label and accessible testing information while the evidence for a particular advertised outcome remains uncertain. Conversely, a promising ingredient study is not a batch report for the bottle in your parcel. Good comparison work gives each kind of evidence its own job.
Compare the commitment rather than the cheapest headline
Use a common period and record the cash you would actually pay within it. Include introductory charges, ongoing orders, shipping and any consultation or service fees that are quoted separately. A vial, a bottle and an appointment are different purchasing units. Dividing each price by a month will not repair missing information about quantity or renewal timing.
A hypothetical $120 first order followed by $180 renewals has a different cost pattern from a flat $150 subscription, even though the first headline looks cheaper. Treat that as a budgeting example, not a provider price. Our cost worksheet keeps the inputs visible so you can change them when a written quote arrives.
Before choosing, ask what you lose by being wrong about your expectations. A single bottle, a prepaid package and a clinical service already sent to a pharmacy can have different exit conditions. I would prefer the offer I understand clearly over the offer with the most impressive mechanism diagram. If the evidence does not settle your outcome question, say so explicitly in your comparison and discuss suitability with a qualified clinician.
One concrete way to compare is to ask each seller for a one-page offer summary. Put the selected ingredient and route at the top, then the quantity, first charge, ongoing charge, renewal date and contact for questions. Leave any unanswered field visible. If two offers still differ in format, treat the comparison as a choice between routines rather than an effectiveness ranking. That makes the decision more honest and usually easier: you can see which practical tradeoffs you are accepting without pretending a dollar-per-milligram calculation has answered the medical question.
For capsule offers, the supplement label comparison keeps ingredient, serving and package cost together without ranking medical effects.
Sources
- Martens et al. Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults (2018)↩ 1 ↩ 2
- Grant et al. A Pilot Study Investigating Changes in the Human Plasma and Urine NAD+ Metabolome During a 6 Hour Intravenous Infusion of NAD+ (2019)↩ 1 ↩ 2
- Yoshino et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women (2021)↩ 1 ↩ 2
- FDA: Understanding the Risks of Compounded Drugs↩