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Can a pre-workout actually help with sexual performance?
It's a fair question — and the honest answer is "indirectly, and partly." Let's set expectations clearly before getting into the science.
4 Gauge is formulated as a pre-workout for training: energy, focus, pumps and endurance. It is not a treatment for erectile dysfunction (ED) or any sexual-health condition, and it contains no medications or hormones. But sexual performance and athletic performance share a surprising amount of physiology — nitric oxide, blood flow, vascular health, and stress — and several 4 Gauge ingredients have been studied for effects on those exact systems.
This page reviews that research ingredient by ingredient, honestly, including where the evidence is strong, where it's preliminary, and where it comes from related (not identical) products. If you have a genuine sexual-health concern, the right move is a conversation with a qualified healthcare provider — not a scoop of pre-workout.
Important
This article is educational. 4 Gauge is a pre-workout supplement, not a medical treatment. Nothing here is a substitute for professional medical advice, diagnosis or treatment. Persistent erectile or sexual difficulties can signal an underlying health issue worth discussing with a clinician.
The Connection
Why training ingredients overlap with sexual function
The link comes down to one molecule and one system: nitric oxide, and the body's response to stress.
An erection is fundamentally a vascular event. Arousal triggers the release of nitric oxide (NO) in penile tissue, which relaxes smooth muscle and lets the arteries dilate and fill with blood. This is the very same pathway that ED medications like sildenafil (Viagra) act on — they work downstream, while ingredients such as L-citrulline and beet root work upstream by supplying more of the raw materials for NO production.5 The same blood-flow improvements 4 Gauge is designed to deliver for "pumps" during training are driven by this NO system.
The second link is stress and anxiety. Psychological stress and performance anxiety are among the most common contributors to sexual difficulties in both men and women — chronic stress elevates cortisol, which suppresses sex hormones and dampens arousal.11 Ingredients studied for stress resilience and calm focus therefore have a plausible, indirect role.
The blood-flow side
L-Citrulline and beet root raise nitric oxide and support vasodilation — the physiology behind both pumps and erections.
The stress side
Rhodiola and L-Theanine are studied for lowering cortisol and anxiety — common psychological barriers to arousal.
Where They Overlap
The five systems these ingredients touch
Each relevant 4 Gauge ingredient maps to one or more of the physiological systems behind sexual function. Select a card to jump to its evidence.
Key Research Findings
What the literature consistently shows
Plain-language summaries of the most relevant findings across the ingredients.
01
In men with mild ED, oral L-citrulline significantly improved erection hardness versus placebo — 50% reached the firmest score vs 8.3% on placebo.2
02
An L-citrulline + beet root combination raised nighttime erection quality by ~33% on objective (RigiScan) monitoring.6
03
That same NO-boosting combination added to low-dose sildenafil outperformed sildenafil alone for nighttime erections.7
04
In burnout patients, Rhodiola rosea significantly improved sexual-function scores alongside lower fatigue and cortisol.8
05
Men with vascular-origin ED have measurably lower arginine and citrulline levels — the substrates these ingredients supply.1
Ingredients & Evidence
The relevant ingredients, on the record
Five 4 Gauge ingredients have research connecting them to the physiology of sexual function. Here's each one, honestly assessed.
Ingredient · 01
L-Citrulline DL-Malate
6,000 mg · the most directly relevant ingredient
Why it's relevant
L-Citrulline raises plasma arginine and, in turn, nitric oxide — the upstream side of the exact pathway ED drugs target downstream. A deficiency in the arginine/citrulline axis is directly associated with vasculogenic ED.1
The human evidence
The pivotal RCT (Cormio et al.) gave men with mild ED oral L-citrulline and saw significantly improved erection hardness scores versus placebo, with 50% of the citrulline group reaching the hardest score versus 8.3% on placebo — and no adverse events.2 A crossover pilot found citrulline (with trans-resveratrol) added benefit on top of PDE5 inhibitors,3 animal work confirmed the vascular mechanism,4 and a broader review details NO's role in both peripheral and central (brain) aspects of erection.5
Reviewed by the 4 Gauge research team
Ingredient · 02
Red Beet Root (+ L-Citrulline Synergy)
300 mg · a second, independent nitric-oxide pathway
Why it's relevant
Beet root supplies dietary nitrate that the body converts to nitric oxide through a pathway independent of the enzymatic route citrulline uses — so the two together amplify NO from two directions, including in the low-oxygen conditions of resting tissue.
The human evidence
This is where the combination gets interesting. A clinical trial (Brandeis & Justin, 2024) tested an L-citrulline + beet root supplement and measured nighttime erections objectively with RigiScan: erection quality (area-under-the-curve) rose from 11.9 to 15.8 per hour — about a 33% improvement (p = 0.0001).6 A 2025 follow-up found the same NO-boosting combination added to low-dose sildenafil produced 34% higher nighttime erection quality than sildenafil alone (p = 0.00004).7
Reviewed by the 4 Gauge research team
Ingredient · 03
Rhodiola Rosea
100 mg · the stress-and-libido angle
Why it's relevant
Psychological stress is a leading driver of sexual dysfunction. Chronic stress raises cortisol, which suppresses the hormonal axis governing sex drive and dampens dopaminergic arousal. Rhodiola is an adaptogen studied for modulating the HPA axis and reducing cortisol reactivity.11
The human evidence
A multicenter study of burnout patients (Kasper & Dienel, 2017) measured sexual function as an explicit endpoint and found significant improvement over 12 weeks of Rhodiola, alongside reductions in fatigue and cortisol.8 A review notes Rhodiola's traditional use even included impotence,9 and a case report documented recovery of anxiety-induced female sexual dysfunction with a protocol built around Rhodiola.10
Reviewed by the 4 Gauge research team
Ingredient · 04
L-Theanine
200 mg · for the performance-anxiety barrier
Why it's relevant
Performance anxiety is one of the leading causes of psychogenic erectile difficulty in men, and anxiety disrupts the parasympathetic activity needed for arousal in women. L-Theanine promotes a calm, focused state without sedation by modulating glutamate and increasing GABA activity — lowering the psychological barrier to arousal, especially paired with Rhodiola.
The human evidence
L-Theanine was an explicit component of the naturopathic protocol that resolved anxiety-induced female sexual dysfunction in the Nazareth & Gilbert case report.10 Its well-documented anxiolytic effects are supported by RCTs — 200 mg/day significantly reduced anxiety, stress and sleep disturbance in healthy adults.12
Reviewed by the 4 Gauge research team
Ingredient · 05
Acetyl L-Carnitine
200 mg · a supporting vascular role
Why it's relevant
Carnitine isn't a primary sexual-performance ingredient, but its role in mitochondrial energy and vascular antioxidant defense gives it a supporting part. Oxidative stress in penile vasculature is a recognized contributor to ED, impairing NO availability and endothelial function.14
The human evidence
A clinical trial found propionyl-L-carnitine combined with sildenafil significantly improved erectile and orgasmic function versus sildenafil alone in men with diabetes-related ED.13 Note this used a related carnitine form at higher doses than a pre-workout provides, so the relevance is mechanistic and supporting rather than direct.
Reviewed by the 4 Gauge research team
Evidence Summary
The ingredients at a glance
| Ingredient | Dose | Relevance to sexual function | Evidence |
|---|
| L-Citrulline |
6,000 mg |
Upstream NO production; improved erection hardness in mild ED |
Strong |
| Red Beet Root |
300 mg |
Dietary-nitrate NO pathway; +33% nighttime erections with citrulline |
Strong |
| Rhodiola Rosea |
100 mg |
Cortisol/stress reduction; sexual function measured in a trial |
Moderate |
| L-Theanine |
200 mg |
Anxiolytic; used for anxiety-induced sexual dysfunction |
Moderate |
| Acetyl L-Carnitine |
200 mg |
Vascular antioxidant support; benefit shown at higher doses |
Supporting |
The Practical Question
Should you take pre-workout before sex? Good or bad?
It's the question our blog tackles head-on — and the honest answer is "it depends on you and the timing."
The potential upside
The nitric-oxide ingredients support blood flow, the caffeine can boost energy and confidence, and L-Theanine helps keep that energy calm rather than jittery. For some people, that combination feels genuinely helpful.
The potential downside
Caffeine affects everyone differently. In sensitive people it can cause jitters, a racing heart or anxiety — the opposite of what you want. Timing matters too: taken too late, caffeine can disrupt sleep.
The nitric-oxide and stress-related ingredients build their benefits with consistent daily-to-regular use rather than acting like an on-demand pill, so think of 4 Gauge's relevance here as supporting the underlying systems over time — not as a moment-of pre-dose. If you do experiment, a smaller serving and earlier timing tend to be more comfortable, and anyone sensitive to stimulants should be cautious.
The Honest Bottom Line
What this research does — and doesn't — mean
We'd rather give you an accurate picture than an overhyped one.
What the evidence supports: several 4 Gauge ingredients — especially L-citrulline and beet root — act on nitric oxide, blood flow and stress, which are core to sexual function, and some have direct human data (including objective erection measurements). The strongest findings come from studies on those specific ingredients and combinations.
What it doesn't mean: 4 Gauge is still a pre-workout, dosed and designed for training. Some of the sexual-health studies used different doses, different forms, or related (not identical) products, and individual results vary widely. 4 Gauge is not a treatment for erectile dysfunction or any sexual-health condition, and it should not replace medical care. Persistent sexual difficulties can be an early sign of cardiovascular or hormonal issues — which is exactly why a conversation with a qualified healthcare provider is the right first step.
Built for training — powered by blood flow
4 Gauge delivers smooth energy, focus and serious pumps through the same nitric-oxide pathways discussed here. Explore the formula and the research behind each ingredient.
- 6,000 mg L-Citrulline
- Dual nitric-oxide pathways
- Smooth energy, no crash
- No proprietary blends
Continue Your Research
Keep exploring the Research Hub
More evidence-based ingredient and topic deep dives from the 4 Gauge Research Hub.
About the Author
Who wrote and reviewed this page
Author & Reviewer
Connor Southworth
Founder, 4 Gauge
Connor Southworth is the founder of 4 Gauge and has spent years researching, formulating and manufacturing premium nutritional supplements. He personally oversees product development and ingredient selection, with a focus on evidence-based formulations designed to support performance, recovery and long-term health.
10+ yrsIn nutrition
Evidence-ledFocus
June 2026Last reviewed
June 2027Next review
FAQ
Pre-workout & sexual performance: common questions
Can 4 Gauge help with erectile function?
4 Gauge is a pre-workout, not an ED treatment, and we don't market it as one. That said, two of its ingredients — L-citrulline and beet root — act on the nitric-oxide blood-flow pathway central to erections, and that specific combination has shown measurable improvements in nighttime erection quality in research. If you have persistent erectile difficulties, see a healthcare provider, as it can signal an underlying issue.
Which ingredient matters most for blood flow?
L-Citrulline (6,000 mg) is the most directly relevant — it boosts nitric oxide upstream, the same pathway ED medications use downstream. Beet root adds a second, independent nitric-oxide pathway, and the two have been studied together for erection quality.
Is it a good idea to take pre-workout before sex?
It depends on you. The blood-flow ingredients and caffeine energy can feel helpful for some, but caffeine causes jitters, a racing heart or anxiety in sensitive people, and late dosing can disrupt sleep. A smaller, earlier serving is gentler. We dig into the trade-offs in our blog, "Pre-Workouts Before Sex: Good or Bad?"
Does it work for women too?
The blood-flow and erection research is male-specific, but the stress and anxiety pathways apply to everyone — anxiety and elevated cortisol impair arousal in both men and women, and a case report documented improvement in anxiety-induced female sexual dysfunction with a Rhodiola- and L-theanine-based protocol. Evidence in women is more limited overall.
How quickly would any benefit appear?
The nitric-oxide and stress-related ingredients build their effects with regular, consistent use rather than acting like an on-demand pill. Think of them as supporting the underlying systems over time, not a moment-of fix.
Sources & References
The research behind this page
Grouped by mechanism. Human RCTs and clinical studies are weighted above mechanistic or case-report data.
01 · TopicNitric Oxide & Blood Flow (L-Citrulline + Beet Root)
- 1.Barassi A, et al. "Levels of L-arginine and L-citrulline in patients with erectile dysfunction of different etiology." Andrology, 2017;5(2):256–261. doi:10.1111/andr.12293
- 2.Cormio L, et al. "Oral L-Citrulline Supplementation Improves Erection Hardness in Men With Mild Erectile Dysfunction." Urology, 2011;77(1):119–122. View source
- 3.Iwasa A, et al. "Oral L-citrulline and Transresveratrol Supplementation Improves Erectile Function in Men With PDE5 Inhibitors: A Randomized, Double-Blind, Placebo-Controlled Crossover Pilot Study." Urol Int, 2018;101(3):286–291. PMC6302103
- 4.Shiota A, et al. "Oral L-citrulline supplementation improves erectile function in rats with acute arteriogenic erectile dysfunction." J Sex Med, 2013;10(10):2423–2429. View source
- 5.Argiolas A, Melis MR. "Erectile Function and Sexual Behavior: A Review of the Role of Nitric Oxide in the Central Nervous System." Biomolecules, 2021;11(12):1866. View source
- 6.Brandeis J, Justin B. "L-Citrulline and Beet Root Supplement Improves Nighttime Erections." J Sex Med, 2024;21(Suppl 1) [abstract]. View source
- 7.Brandeis J, et al. "Combining a Nitric Oxide Boosting Dietary Supplement With Sildenafil Improves Nighttime Erections More Than Sildenafil Alone." J Sex Med, 2025;22(Suppl 1) [abstract]. View source
02 · TopicStress, Anxiety & Libido (Rhodiola + L-Theanine)
- 8.Kasper S, Dienel A. "Multicenter, open-label, exploratory clinical trial with Rhodiola rosea extract in patients suffering from burnout symptoms." Neuropsychiatr Dis Treat, 2017;13:889–898. View source
- 9.Stojcheva EI, Quintela JC. "The Effectiveness of Rhodiola rosea L. Preparations in Alleviating Various Aspects of Life-Stress Symptoms." Pharmaceuticals, 2022;15(6):740. PMC9228580
- 10.Nazareth T, Gilbert C. "Anxiolytic Herbs and Naturopathic Treatment of Anxiety-Induced Female Sexual Dysfunction: A Case Report." Can J Naturopath Med, 2022;1(1). View source
- 11.Azam M, Nadeem M. "Impact of Psychological Stress on Male Sexual Performance." J Soc Educ, 2026. View source
- 12.Hidese S, et al. "Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial." Nutrients, 2019;11(10):2362. PMC6836118
03 · TopicVascular Support (Acetyl L-Carnitine)
- 13.Gentile V, et al. "Propionyl-L-carnitine, L-arginine, and niacin in sexual and reproductive medicine." Urology, 2004. PubMed 15882737
- 14.Zhu Y, et al. "Erectile Dysfunction and Oxidative Stress: A Narrative Review." Int J Mol Sci, 2025;26(7):3073. View source
