MEDVi QUAD Dosage: What's in Each Dose, How to Take It, and What to Expect

If you're considering MEDVi QUAD or just got your first bottle, this guide walks through the ingredient breakdown for the reformulated blend, how sublingual dosing actually works, when to take it, and the side effect profile you should know about beforehand.

What's Actually Inside Each Dose

QUAD is a compounded medication, which means a licensed pharmacist combines the ingredients to order based on a physician's prescription. Since the July 16, 2026 reformulation, each dose contains these four ingredients:

We're not going to publish milligram figures for this formula, because there aren't fixed ones to publish. QUAD is compounded, and the amount of each ingredient is set by the prescribing physician during your consultation. This isn't a one-size-fits-all tablet pulled off a shelf. The physician reviews your health history, current medications, and severity of symptoms before settling on the right combination.

One thing worth being straight about: two of these four ingredients are FDA-approved ED drugs, and two are not. L-citrulline is a supplement-grade amino acid. PT-141 is FDA-approved, but for low sexual desire in premenopausal women — its use in a men's ED formula is off-label and prescriber-supervised. What you can say about all four is that each has published human clinical evidence for sexual function. That's a narrower claim than "clinically proven for ED," and it's the accurate one.

What Each Ingredient Does (and Why There Are Four)

Before July 2026, QUAD stacked three PDE5 inhibitors — sildenafil, tadalafil, and vardenafil — plus apomorphine. The new formula drops vardenafil and apomorphine and takes a different approach: two PDE5 inhibitors, one ingredient that feeds the nitric-oxide pathway those inhibitors depend on, and one that works on desire in the brain instead of on blood flow.

The two PDE5 inhibitors aren't redundant. The answer has to do with pharmacokinetics — how each drug behaves in your body over time. They're not interchangeable.

Sildenafil — the workhorse

Sildenafil has been the gold standard since 1998. It kicks in within 30–60 minutes as a pill (faster sublingual), reaches peak effectiveness at about 1 hour, and maintains strong effects for 4–6 hours. It's the most extensively studied ED drug in existence. The trade-off: it's sensitive to food. A fatty meal can delay absorption by an hour or more when taken as a pill. QUAD gets around this because sublingual delivery skips the stomach entirely.

Tadalafil — the marathon runner

Where sildenafil is a sprinter, tadalafil is the long game. Its effects can persist for up to 36 hours, which is why Cialis earned the nickname "the weekend pill." It doesn't hit quite as hard at peak, but it gives you a wide window where spontaneity is possible. No watching the clock.

L-Citrulline — the nitric-oxide amplifier

L-citrulline is an amino acid, not a drug. Your body converts it to L-arginine, which raises nitric-oxide production, which supports blood-vessel dilation. That's the same pathway PDE5 inhibitors depend on — sildenafil and tadalafil work by preventing the breakdown of the signal downstream, while L-citrulline works on the supply side. The evidence here is early but real: a small single-blind study of 24 men (Cormio et al., Urology, 2011) found oral L-citrulline improved erection hardness in men with mild ED, with 50% of men improving versus 8% on placebo. Twenty-four men is a small trial, and this is a supplement-grade ingredient rather than an FDA-approved ED drug. Treat it as a genuine but modest supporting player, not a headline act.

PT-141 (bremelanotide) — the desire ingredient

PT-141 replaces apomorphine as the ingredient that addresses desire rather than plumbing. It activates melanocortin receptors in the brain, targeting sexual desire and arousal centrally instead of increasing blood flow. PDE5 inhibitors can improve blood flow all they want, but if the brain isn't sending the "go" signal, blood flow alone may not be enough.

Here's the honest status: PT-141 is FDA-approved as Vyleesi (2019), by injection, for low sexual desire (HSDD) in premenopausal women. In men, early-phase trials of intranasal bremelanotide showed erectogenic effects, including in some men who didn't respond to sildenafil — but it was never approved for ED, and development stopped partly over blood-pressure concerns. Its use in QUAD is compounded, off-label, and prescriber-supervised. What sets it apart from the desire ingredient in competing formulas is the evidence base: PT-141 has human clinical trial data and an FDA approval in another indication. Oxytocin, the desire ingredient in BlueChew Gold, has neither.

How to Take QUAD — Step by Step

QUAD comes as a sublingual liquid, not a pill. The difference matters more than most people realize.

Step 1: Measure the dose using the provided dropper or measurement tool. Your prescribed dose will be specified by your clinician — don't eyeball it.

Step 2: Place the liquid under your tongue. The underside of the tongue has a dense network of blood vessels close to the surface. This is where sublingual absorption happens.

Step 3: Hold it there for 60–90 seconds. Resist the urge to swallow immediately. The longer the liquid stays in contact with the sublingual membrane, the more gets absorbed directly into your bloodstream. After 60–90 seconds, swallow whatever remains.

Step 4: Wait approximately 10–15 minutes for onset. Most men report feeling the initial effects within this window. Full effects develop over 30–60 minutes.

Timing: When to Take It and How Long It Lasts

One of the biggest advantages of QUAD over traditional ED pills is timing flexibility. Because the sublingual liquid absorbs directly through the mouth's blood vessels, it doesn't need to pass through your stomach or liver first. The practical effect:

Onset: 10–15 minutes. This is roughly 2–4x faster than swallowing a sildenafil pill, which typically needs 30–60 minutes on an empty stomach.

Peak effectiveness: 30 minutes to 2 hours after taking, depending on the individual. The sildenafil component drives this window.

Total duration: Up to 36 hours. The tadalafil component is what stretches this out. You won't feel peak effects for 36 hours — but the medication remains active in your system, meaning you can respond to arousal naturally during that window without needing another dose.

Practically speaking, most men take it 15–30 minutes before anticipated sexual activity. But the long duration means you don't have to time it precisely. Take it after dinner, and you're covered through the next morning — and beyond.

Food, Alcohol, and Other Interactions

Food: Not an issue. This is one of the underrated benefits of sublingual delivery. Traditional sildenafil pills lose significant effectiveness when taken with a heavy meal — the drug has to compete with food for absorption in the digestive tract. QUAD bypasses the digestive system entirely, so eat whatever you want beforehand.

Alcohol: Moderate alcohol consumption (one or two drinks) is generally fine, but alcohol is itself a vasodilator and can compound the blood-pressure-lowering effects of PDE5 inhibitors. Heavy drinking can also dampen sexual response, which works against what the medication is trying to do. Practically: a glass of wine at dinner won't be a problem. Half a bottle might be.

Grapefruit: This is the one people forget about. Grapefruit and grapefruit juice inhibit CYP3A4, the liver enzyme that metabolizes sildenafil and tadalafil. This can increase drug levels in your blood and amplify side effects. Avoid grapefruit within a few hours of taking QUAD.

Side Effects — What's Normal and What's Not

The two PDE5 inhibitors in QUAD have well-documented side effect profiles from decades of clinical use, and that's where most of what you'll notice comes from. The two newer ingredients have a thinner record, which we'll be upfront about below. Here's what to realistically expect.

Common (most men experience at least one)

Nausea — expect this on the first dose. This is the side effect most reviews of the new formula leave out, and it is the one most likely to affect you. PT-141's FDA-approved form, Vyleesi, reported nausea in 40% of patients across the pooled phase 3 trials versus 1% on placebo. It is strongly front-loaded: 21% after the first dose, falling to about 3% on later doses. Onset is typically within an hour and it lasts roughly two hours. In those trials 13% of patients used an anti-emetic and 8% quit over it.

The important qualifier is that those figures come from a 1.75 mg subcutaneous injection given to women with HSDD, not from sublingual PT-141 in a compounded men's formula at a dose MEDVi doesn't publish. A different route and dose can mean a different rate, so read 40% as the ceiling from the best-documented version of the drug rather than a forecast for QUAD. Practically: take your first dose on an evening with no obligations, and tell your prescriber if it does not settle after the first few uses. QUAD's old formula had this issue too, since apomorphine is also strongly linked to nausea — the reformulation moved the problem rather than removing it.

Headache — the most frequently reported side effect of PDE5 inhibitors across all clinical trials. Usually mild, peaks about an hour after dosing, resolves within a few hours. Over-the-counter pain relief helps. Often diminishes with repeated use as your body adjusts.

Nasal congestion — PDE5 inhibitors relax smooth muscle everywhere, including nasal passages. This is a feature, not a bug, but it can feel like sudden stuffiness.

Facial flushing — warmth or redness in the face and neck. Caused by blood vessel dilation. Harmless, but visible. Tends to fade within 1–2 hours.

Mild dizziness — usually when standing up quickly. The blood pressure effect of PDE5 inhibitors can cause orthostatic lightheadedness, particularly in the first hour. Move slowly when getting up from a seated or lying position.

Less common

Blood pressure effects tied to PT-141 — worth knowing about rather than glossing over. Bremelanotide's development for ED in men was halted partly over blood-pressure concerns, and its use in QUAD is off-label and compounded. That's precisely why a prescribing physician screens your cardiovascular history and sets the dose, instead of you picking a strength off a menu.

Blue-tinted vision — a known sildenafil effect at higher doses. Temporary. Objects may look slightly blue-tinged for a few hours.

Back pain or muscle aches — more associated with tadalafil. Usually appears 12–24 hours after dosing and resolves within a day.

Serious (rare, but requires immediate attention)

Priapism — an erection lasting more than 4 hours. This is a medical emergency. Go to an emergency room.

Sudden hearing or vision changes — reported in extremely rare cases with PDE5 inhibitors. Stop use and see a doctor immediately.

Severe hypotension — dangerous drop in blood pressure. Risk is highest when combined with nitrates (which is why it's contraindicated) or excessive alcohol.

Storage: Does QUAD Need Refrigerating?

No. QUAD is stored at room temperature. It is a sublingual liquid, so there is no refrigeration requirement, it does not ship with ice packs, and you can keep it in a bedside drawer or carry it in a bag without it degrading.

This question comes up constantly, and the reason is Rugiet Ready. Rugiet uses a solid troche, and solid troches have a real temperature problem: they begin to soften above 70°F (21°C) and can liquify completely in genuinely warm conditions. Rugiet ships with ice packs and recommends refrigerator storage. If you have read about that and assumed every sublingual ED product has the same constraint, it is a fair assumption — it just does not apply here. QUAD is already a liquid, so there is nothing to melt.

Practically, this is one of the more underrated differences between the two. A product that needs refrigeration is awkward to travel with, awkward to keep discreetly, and awkward in summer. A room-temperature liquid is none of those things.

How QUAD Dosing Compares to Pills

The meaningful differences are speed and comprehensiveness. You get faster onset because the drug doesn't need to survive your digestive tract, and you get broader mechanism coverage because four ingredients are working simultaneously.

For a deeper comparison with specific competitors, see our Rugiet vs BlueChew vs QUAD comparison or our full MEDVi QUAD review.

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