Two products, sold as a stack, usually offered as a free trial. The ingredients question has a real answer. The billing question has a much more expensive one.
On the ingredients: the nitric-oxide half of this kind of stack is built on L-arginine or L-citrulline. There’s a genuine pharmacological difference between them — 40–50% of an oral arginine dose is degraded by arginase in the gut and liver before it reaches circulation, while citrulline has roughly 97% oral bioavailability and raises plasma arginine about 30% more effectively than arginine itself. So if a “nitric oxide” product is built on arginine, it’s built on the weaker of the two.
On the free trial: this is where the real money is. In January 2023 the FTC sent more than $973,000 to 17,064 people after NutraClick LLC automatically enrolled them in unwanted membership programmes for supplements and beauty products. Roughly 70,000 consumers complained of being billed $29.99 to $79.99 every month after a trial period. That’s the pattern to understand before you enter a card number. 💳
- The two-product stack pattern
- What “nitric oxide boosters” actually do
- Arginine vs citrulline: the real difference
- What’s usually in the “alpha” half
- Proprietary blends and why they matter
- The FTC case worth knowing about
- ROSCA: the law that protects you
- How the free trial actually works
- How to protect yourself before ordering
- If you’ve already been billed
- What to buy instead
- Frequently asked questions
- Your checklist
The two-product stack pattern
Before anything else, notice the structure — because the structure is the product.
You are rarely offered one supplement. You’re offered two that “work together”: a nitric oxide product for pumps and blood flow, and an “alpha” or “complex” product for muscle and testosterone. The pairing is presented as synergy.
What the pairing reliably does is double the number of subscriptions. Two trials, two card authorisations, two recurring charges, two cancellation processes — often through two different customer service numbers with different terms.
Ask yourself why a product that works needs a second product to work alongside it, and why both need your card details today.
We should be clear about what we can and can’t say here. We have not found any regulatory action or court finding against products marketed under these particular names, and nothing in this article alleges wrongdoing by any specific seller. What we can do is explain what’s in this category of product, and document what the FTC has established about how this style of offer has been run by companies it did take action against.
What “nitric oxide boosters” actually do
The mechanism is real, which is why this category persists.
Nitric oxide is a signalling molecule that causes blood vessels to dilate. More dilation means more blood flow, which in a training context means a more pronounced “pump,” and potentially some benefit to exercise performance and recovery.
Your body makes nitric oxide from the amino acid L-arginine. So the logic of the supplement is straightforward: take more arginine, make more nitric oxide, get more blood flow.
The logic is sound. The execution is where most of these products fall down — and the reason is a single enzyme.
Arginine vs citrulline: the real difference
This is the single most useful piece of information in the article for anyone shopping this category.
Oral L-arginine is extensively destroyed before it can do anything. It is broken down by arginase enzymes in the intestinal mucosa and by hepatic first-pass metabolism, with as much as 40 to 50% of an oral dose degraded before it reaches systemic circulation.
L-citrulline sidesteps that problem entirely. Citrulline is not a substrate for arginase, so it bypasses first-pass degradation, is absorbed in the small intestine with roughly 97% oral bioavailability, and is then converted to arginine in the body. Citrulline also acts as an allosteric inhibitor of arginase, which further protects the arginine that is there.
The practical result is counter-intuitive and well documented: L-citrulline raises plasma L-arginine levels approximately 30% more effectively than taking L-arginine itself.
| L-arginine | L-citrulline | |
|---|---|---|
| Oral bioavailability | Substantially reduced | ~97% |
| Destroyed by arginase? | Yes — 40–50% of a dose | No — not a substrate |
| Effect on plasma arginine | Baseline comparison | ~30% more effective |
| Effect on arginase itself | None | Allosteric inhibitor |
| Which to look for on a label | Weaker choice | Better choice |
Turn the bottle over. If the nitric oxide ingredient is L-arginine (or AAKG, arginine alpha-ketoglutarate), you are looking at the version with the bioavailability problem. If it’s L-citrulline or citrulline malate, the formulator understood the pharmacology. This one check separates products designed around the science from products designed around a familiar-sounding ingredient name — and it costs you nothing.
What’s usually in the “alpha” half
The second product in these stacks is typically positioned around testosterone, muscle or “male performance,” and the ingredient lists are far more variable. Common inclusions and where the evidence sits:
| Ingredient | Claim | Evidence position |
|---|---|---|
| Tribulus terrestris | Raises testosterone | Weak — does not reliably raise testosterone in healthy men |
| Fenugreek | Testosterone, libido | Mixed, small studies |
| Horny goat weed | Libido, performance | Weak human evidence |
| Maca | Libido, energy | Some libido signal; not a testosterone effect |
| Zinc | Testosterone support | Matters if deficient; not a booster if you’re replete |
| Saw palmetto | Prostate, hormones | Studied for prostate symptoms, not muscle |
| Caffeine | Energy, focus | Genuinely works — and explains why you “feel it” |
| Creatine (if present) | Strength, lean mass | Strongest evidence in sports nutrition |
Two things are worth pulling out of that table. First, zinc “supporting testosterone” is a real thing only if you’re deficient — correcting a deficiency is not the same as boosting a normal level, and the marketing routinely blurs the two. Second, if the blend contains caffeine, that is very likely the source of whatever you feel on day one. That sensation is real and it is also not evidence that anything else in the capsule is working.
Proprietary blends and why they matter
Many products in this category list ingredients inside a proprietary blend — a single total weight covering six or twelve ingredients, with no individual amounts disclosed.
This is legal, and it is also the end of your ability to evaluate the product. A “1,200 mg Alpha Matrix” could be 1,150 mg of a cheap filler amino acid and 50 mg spread across everything the marketing talks about. You cannot tell, and you cannot compare it against the doses used in any study.
Treat an undisclosed blend as a missing ingredient list. Where a product does disclose amounts, that’s a meaningful signal about the seller’s confidence in what’s inside.
The FTC case worth knowing about
Now the part that costs people real money. We’re citing a specific, documented enforcement action — against a specific company — because it establishes the pattern precisely.
In January 2023, the Federal Trade Commission announced it was sending payments totalling more than $973,000 to 17,064 people who lost money after NutraClick LLC automatically enrolled them in unwanted membership programmes for supplements and beauty products, and misled consumers about when they had to cancel trial memberships to avoid monthly charges.
| Element | Detail |
|---|---|
| Company | NutraClick LLC |
| Conduct alleged | Auto-enrolment in unwanted membership programmes; misleading consumers about the cancellation deadline |
| Laws cited | FTC Act and ROSCA |
| Settlement | $1.04 million |
| Returned to consumers | More than $973,000 |
| People paid | 17,064 |
| Complaints | Approximately 70,000 consumers |
| Monthly charges complained of | $29.99 to $79.99 per month |
| Payments began | 25 January 2023 |
Read the last two rows together. Roughly 70,000 complaints, and 17,064 people received money. The gap between those numbers is the most instructive part of the case: even with a successful federal enforcement action and a seven-figure settlement, most people who complained did not end up in the refund distribution.
Federal enforcement works, but it is slow, partial and years after the fact. Being made whole is not the default outcome — it’s the exception that a large, successful case occasionally produces. The four minutes you spend reading the terms before you enter your card number are worth more than every consumer protection mechanism downstream of that moment. This is not a reason to distrust the FTC; it’s a reason to understand what the process can realistically do for you.
ROSCA: the law that protects you
ROSCA — the Restore Online Shoppers’ Confidence Act — is the federal law that governs exactly this kind of offer, and it’s worth knowing that it exists.
Broadly, a seller using a negative-option online offer — where your silence becomes consent to be billed — has to clearly and conspicuously disclose the terms before obtaining your billing information, obtain your informed consent, and provide a simple mechanism to stop the recurring charges.
In the NutraClick matter, the FTC’s position was that failing to clearly disclose that consumers would be automatically billed if they did not cancel within a trial period violated federal continuity plan law.
What that means for you practically: if a checkout page buries the recurring terms, or makes cancelling far harder than signing up was, that asymmetry is not just annoying — it’s the exact thing the statute addresses. Screenshot it.
How the free trial actually works
The mechanics are consistent enough to describe as a sequence:
- You pay shipping only. A small amount — often under $10 — which frames the transaction as low risk and captures your card.
- The trial clock starts at order, not delivery. This is the crucial detail. A 14-day trial that begins when you click, minus five days of shipping, is a nine-day trial in practice.
- The terms live below the fold, in smaller text, or behind a link you have no reason to open.
- The first real charge lands — the FTC case describes complaints of $29.99 to $79.99 monthly.
- The second product bills separately, on its own schedule, sometimes from a differently named merchant on your statement.
- Cancellation requires a phone call during limited hours, with retention offers designed to keep you on the line.
Notice that step 2 does most of the work. By the time the product physically arrives and you decide whether you like it, a meaningful fraction of the evaluation window is already gone.
How to protect yourself before ordering
1. Find the recurring terms and read them. If you cannot locate them in sixty seconds, that is your answer. 2. Screenshot everything — the offer page, the terms, the checkout confirmation, the cancellation instructions. 3. Establish when the trial clock starts — order date or delivery date. 4. Note the cancellation deadline in your calendar with a reminder three days early. 5. Find the cancellation method before you buy, not after. 6. Check whether both products bill separately — cancel one and you may still be paying for the other.
One further protection worth considering: many banks and card issuers offer virtual or single-use card numbers with spending limits, and some let you block a specific merchant from recurring charges. Using one for a trial offer means the recurring charge simply fails rather than becoming a dispute you have to win.
If you’ve already been billed
A practical sequence, in order:
- Cancel first, dispute second. Stop the bleeding before you argue about the past. Get a cancellation confirmation number and the name of the person you spoke to.
- Cancel both products separately. Do not assume one call covers the stack.
- Contact your card issuer. Dispute unauthorised recurring charges and ask them to block further charges from that merchant.
- Gather your evidence — order confirmation, the terms as they appeared, statements showing each charge, notes of every call with dates.
- Report it to the FTC at ReportFraud.ftc.gov. Individual reports are what build the cases that produce actions like the one above.
- Report to your state attorney general, who may have consumer protection remedies of their own.
- Don’t accept a partial refund as final if you were charged for months you didn’t authorise — but do get any offer in writing.
L-Citrulline Malate Powder
Bought outright, dose visible, no trial, no subscription, no second product
If you want the nitric-oxide mechanism, buy the compound the pharmacology actually supports. L-citrulline has roughly 97% oral bioavailability, isn’t degraded by arginase the way arginine is, and raises plasma arginine about 30% more effectively than arginine itself. Buying a single-ingredient powder gives you three things a stacked free trial cannot: you can see the exact dose, you pay once, and there is nothing to cancel. Take it around 60 minutes before training. Start at the lower end and increase gradually — the main practical downside is gastrointestinal discomfort at higher doses, which is dose-dependent and settles when you back off. Citrulline malate is bonded to malic acid and is the form most commonly used in performance studies.
- Citrulline, not arginine — arginase destroys 40–50% of an oral arginine dose
- Start low and build; stomach upset is the main dose-dependent side effect
- Single ingredient means you can see the dose — no proprietary blend
- Do not take it alongside nitrates or erectile dysfunction drugs without medical advice — blood pressure can drop dangerously
- Check with your doctor first if you take any blood pressure medication
What to buy instead
If the underlying goal is muscle and performance rather than a pump you can photograph, the priority order is well established and unexciting:
- Creatine monohydrate. The best-evidenced supplement in sports nutrition, and among the cheapest. Our piece on what actually works for building muscle covers the dosing and the protein target that goes with it.
- Enough total protein. A meta-analysis found gains plateaued at 1.62 g/kg/day of total protein — a target, not a product.
- Caffeine, used deliberately. Real effect on perceived effort; blunted by daily heavy use and costly to sleep if taken late.
- L-citrulline, if you specifically want the blood-flow mechanism.
- Nothing else in the “alpha” category has evidence approaching those.
Buy each one separately, in a single-ingredient form, at a visible dose, with no subscription. That’s four decisions you make once, rather than two recurring relationships you have to actively end.
Frequently asked questions
Do nitric oxide supplements work?
The mechanism is real — nitric oxide dilates blood vessels, which increases blood flow. Whether a given product delivers depends heavily on which compound it uses. Oral L-arginine has a serious bioavailability problem: 40–50% of a dose is degraded by arginase in the gut and liver before reaching circulation. L-citrulline avoids that, with roughly 97% oral bioavailability, and raises plasma arginine about 30% more effectively than arginine does. So a citrulline-based product has a much better claim to doing what it says than an arginine-based one.
Is L-citrulline better than L-arginine?
For raising plasma arginine and supporting nitric oxide production, yes — and counter-intuitively so, given citrulline isn’t the compound your body uses directly. Citrulline is absorbed at roughly 97% bioavailability, is not a substrate for arginase so it bypasses first-pass degradation, and additionally acts as an allosteric inhibitor of arginase. The net result is approximately 30% greater effectiveness at raising plasma L-arginine than taking L-arginine itself.
Are these free trial offers legitimate?
Free trials as a concept are legal and some are run properly. What matters is disclosure. ROSCA — the Restore Online Shoppers’ Confidence Act — requires that recurring billing terms be clearly and conspicuously disclosed before billing information is taken, that consent be informed, and that there be a simple way to stop the charges. In January 2023 the FTC sent more than $973,000 to 17,064 people after NutraClick LLC auto-enrolled them in unwanted membership programmes and misled them about cancellation deadlines; around 70,000 consumers had complained of monthly charges of $29.99 to $79.99. Read the terms and screenshot them before entering a card number.
Why are they always sold as two products together?
The stated reason is synergy. The commercial effect is two subscriptions rather than one — two card authorisations, two billing cycles and two separate cancellations, sometimes appearing under different merchant names on your statement. If you decide to cancel, assume nothing carries over: cancel each one individually and get a confirmation number for each.
What is a proprietary blend and should I avoid it?
It’s a single total weight covering multiple ingredients without disclosing how much of each is present. It’s legal, and it makes independent evaluation impossible — a 1,200 mg blend could be almost entirely one cheap ingredient with trace amounts of everything the marketing highlights. You can’t compare it against study doses, so you can’t know whether it’s underdosed. Prefer products that disclose amounts; that disclosure is itself a signal.
What should I do if I’m being billed and can’t cancel?
Cancel first, dispute second — and cancel each product separately, recording a confirmation number and the name of whoever you spoke to. Then contact your card issuer to dispute the unauthorised recurring charges and ask them to block future charges from that merchant. Gather your order confirmation, the terms as they appeared, and statements for every charge. Report it to the FTC at ReportFraud.ftc.gov and to your state attorney general — individual reports are what build cases like the one described above.
Your checklist
- Check whether the NO ingredient is citrulline (good) or arginine (weaker)
- Remember 40–50% of oral arginine is destroyed before it circulates
- Avoid proprietary blends that hide individual doses
- Treat caffeine as the likely source of what you feel on day one
- Know that zinc “supports testosterone” only if you’re deficient
- Find and read the recurring terms before entering a card number
- Screenshot the offer, terms and cancellation instructions
- Establish whether the trial clock starts at order or delivery
- Diary the cancellation deadline with a three-day warning
- Confirm whether both products bill separately
- Consider a virtual or single-use card number for any trial
- If billed: cancel, then dispute, then report to the FTC
- Prefer single-ingredient products bought outright
Medical disclaimer. This article is general information, not medical advice. Do not take L-citrulline, L-arginine or any nitric oxide supplement alongside nitrate medication or erectile dysfunction drugs without medical advice — the combination can cause a dangerous drop in blood pressure. Speak to your doctor first if you take blood pressure medication, have heart or kidney disease, are pregnant or breastfeeding, or are due to have surgery. Stop and seek medical advice if you experience dizziness, fainting, chest pain or palpitations.
Affiliate disclosure. Some links on this page are affiliate links. As an Amazon Associate we earn from qualifying purchases. The product we recommend here is a single, inexpensive ingredient bought outright — specifically because it has nothing to cancel.
