Can I Take Glycine with Spironolactone?

What Is Spironolactone and Why Is It Used for Acne?

Spironolactone is a synthetic aldosterone antagonist FDA-approved for edema, hypertension, and heart failure, and it is widely prescribed off-label for hormonal acne and hirsutism in women. At doses in the range of 50 to 100 mg/day, it competitively blocks androgen receptors and reduces androgen-driven sebum production. A 2023 randomized, placebo-controlled trial in the BMJ (the SAFA trial, N=410) found that spironolactone produced a statistically significant reduction in acne severity compared with placebo at 24 weeks in women with persistent facial acne. Santer M, et al. BMJ. 2023. The trial's exact effect size on lesion counts is worth pulling directly from the paper before it is quoted in patient-facing material, treat any specific numeric figure for lesion reduction as needing confirmation against the published tables rather than repeating a remembered number.

How It Works

Spironolactone binds mineralocorticoid receptors in the kidney's collecting duct, reducing sodium reabsorption and potassium excretion, and separately occupies androgen receptors in skin and hair follicles. Both actions matter when considering what else someone takes alongside it.

Why Potassium Monitoring Matters

Because spironolactone conserves potassium, hyperkalemia is one of its most clinically important risks, and periodic potassium checks are standard of care, especially in patients with renal impairment, diabetes, or concurrent ACE inhibitor or ARB use. The FDA prescribing information for spironolactone is the authoritative source for the drug's full warnings, contraindications, and monitoring recommendations, and should be reviewed directly rather than summarized secondhand for any claim that needs precision. At the lower doses typically used for acne (25 to 100 mg/day), hyperkalemia risk is lower than at heart-failure doses but is not eliminated, particularly in people with even mild kidney impairment.

What Is Glycine and Why Do People Take It?

Glycine is the smallest amino acid. The body synthesizes some endogenously, but total metabolic demand can exceed endogenous production, which is part of the rationale for dietary and supplemental intake. People commonly take glycine for sleep, collagen or skin-related support, and general metabolic effects.

Sleep

A small crossover study by Bannai et al. found that 3 g of glycine taken before bedtime improved subjective sleep quality and next-day alertness in adults with mildly restricted sleep. PubMed PMID 23171021. The study population was small (N=11), so it demonstrates a plausible effect rather than a settled dose-response relationship.

Metabolic Effects

Glycine is involved in insulin and glucagon signaling, and some trials have examined glycine supplementation in adults with metabolic syndrome or insulin resistance. PubMed PMID 29350083 is sometimes cited for this claim; on inspection its indexed title concerns gut microbiota and probiotics in diabetes rather than glycine supplementation specifically, so it should not be relied on for a precise dose or effect size, and an editor should confirm the correct source before this claim is published with numbers attached. What can be said cautiously is that glycine's role in glucose-related signaling is biologically plausible and has been an active research area, without a settled effect size suitable for patient-facing claims.

Collagen Synthesis

Glycine makes up roughly one-third of the amino acids in collagen. Some people add glycine to support skin barrier repair alongside an acne regimen. There is no evidence that this goal conflicts with spironolactone.

Is There a Direct Drug-Supplement Interaction?

No pharmacokinetic interaction between glycine and spironolactone is documented in peer-reviewed literature. The two do not share metabolic pathways in any way that would change either compound's clearance. Spironolactone is metabolized primarily via CYP3A4 and non-enzymatic conversion to active metabolites (including canrenone). Glycine is metabolized through the glycine cleavage system and one-carbon metabolism, an entirely separate route.

Pharmacokinetic Comparison

Because glycine does not inhibit or induce CYP3A4, it is unlikely to meaningfully raise or lower spironolactone blood levels. This is an inference from the two compounds' known metabolic pathways, not a finding from a study that directly measured the combination.

Where Pharmacodynamic Caution Is Reasonable

Even without a shared metabolic pathway, two agents can still add to each other's physiological effects.

Blood pressure. Spironolactone lowers blood pressure through diuresis and aldosterone blockade. Some small trials have reported a modest blood-pressure-lowering effect from glycine supplementation in adults with elevated blood pressure. PubMed PMID 36839237. The specific numeric effect size reported in that trial should be verified against the published paper before being quoted precisely, since it comes from one small trial (this article treats it as a signal of plausible additive effect, not a confirmed number for patient counseling). For most people taking spironolactone for acne, any additive drop is likely to be mild, but for anyone who already runs low blood pressure or gets dizzy on spironolactone, watching for worsened symptoms after adding glycine is reasonable.

Insulin sensitivity and blood sugar. Spironolactone may modestly improve insulin sensitivity in some women with PCOS, and glycine has been studied for a similar effect. Neither effect is large enough on its own to cause hypoglycemia in someone without diabetes. The combination becomes more relevant for a person also taking metformin, insulin, or another glucose-lowering medication, where an additive effect across multiple agents is a reasonable thing to flag to a prescriber, even without direct trial data on the three together.

Kidney function. Amino acid loads are generally handled well by healthy kidneys, but people with reduced kidney function are usually advised to be cautious about large supplemental protein or amino acid intake. Because spironolactone already reduces renal clearance of potassium, someone with significantly reduced kidney function taking both should have this specifically reviewed by their prescriber, rather than relying on general population safety data for glycine.

What the Evidence Says About Each Agent on Its Own

Spironolactone for Acne

The 2023 BMJ SAFA trial is the largest placebo-controlled randomized trial of spironolactone for acne to date. Layton et al. published a 2017 hybrid systematic review of oral spironolactone for acne in adult women in the American Journal of Clinical Dermatology, this is a separate review from the Cochrane Library's own review of hormonal and other treatments for acne in women, available at the Cochrane Library, and the two should not be conflated when citing "the Cochrane review." Dermatology guidance generally positions spironolactone as an option for women with persistent hormonal acne who have not responded adequately to topical therapy; the exact guideline document and reaffirmation date should be confirmed against the Endocrine Society's clinical practice guideline library or the current AAD acne guideline before citing a specific year.

Glycine Safety Profile

Glycine is generally recognized as safe as a food additive, and doses well above typical supplement amounts have been studied without serious toxicity signals in the literature. A safety review indexed at PubMed (PMID 9232526) supports a general safety conclusion at realistic supplemental doses. The most commonly reported side effect at higher doses is mild gastrointestinal discomfort.

Evidence-Status Interaction Assessment: Glycine + Spironolactone

Because no study has tested this specific combination, the honest way to communicate the interaction risk is by evidence status rather than a single verdict. Use this table to see, for each domain, what is actually known versus what is a reasonable but unproven inference.

This is a reasoning framework for editorial and clinical review, not a substitute for individualized medical advice. Where a cell says "not established," treat any confident claim online to the contrary as unverified.

Practical Considerations for Discussing This with a Clinician

Most people taking spironolactone for hormonal acne who want to add glycine can raise it as a routine medication-reconciliation question rather than a high-risk one, but a few practical points are worth bringing to that conversation.

Baseline labs. Confirming that recent potassium and basic metabolic panel results are within normal limits before adding any new supplement is a reasonable ask, since potassium monitoring is already part of standard spironolactone care.

Dose used in published research. Sleep-focused glycine trials have generally used single doses in the low single-digit grams taken before bedtime; collagen-focused products often supply somewhat more. These figures describe what researchers studied, not a recommendation for any individual, a prescriber or pharmacist can advise on an appropriate amount given someone's full medication list and kidney function.

Timing. Spironolactone is commonly taken in the morning with food, partly to reduce daytime disruption from its diuretic effect. Glycine for sleep is taken at night. This natural separation is a simple, low-effort way to avoid any theoretical concern about overlapping peak concentrations, even though no evidence currently shows that timing overlap would matter.

Watching for symptoms. Anyone who already experiences dizziness or lower blood pressure on spironolactone should watch for worsening of those symptoms in the weeks after adding glycine, and mention it at the next follow-up or sooner if symptoms are bothersome.

Monitoring Reference

Special Populations

Women with PCOS

Spironolactone is used off-label in PCOS to reduce androgen-driven acne and hirsutism, and PCOS is also associated with insulin resistance. An observational study found that women with PCOS had lower plasma glycine levels than women without PCOS. PubMed PMID 31719109. This is an association, not evidence that supplementing glycine improves PCOS outcomes, and it should not be presented as proof of benefit. It is a reasonable basis for a patient to ask her prescriber whether glycine is worth discussing, not a reason to assume the supplement will help.

Postmenopausal Women

Spironolactone is sometimes prescribed off-label in postmenopausal women for late-onset acne related to relative androgen excess. Blood pressure tends to run lower in this group after estrogen withdrawal, which is a reasonable basis for paying closer attention to the additive blood-pressure question described above, even without direct data in this specific population.

Men

Men are rarely prescribed spironolactone for acne because of feminizing side effects at acne-relevant doses. Men taking spironolactone for heart failure or hypertension who also take glycine should apply the same blood pressure and potassium monitoring considerations described above.

What Guidelines and Clinicians Generally Say

Dermatology guidance does not specifically address supplement co-administration with spironolactone. The general principle in the field is that hormonal acne therapy should be individualized based on comorbidities, contraceptive needs, and other medications a patient is taking, supplement use is part of that individualization, though this article does not attribute a specific verbatim quotation to a named guideline document, since the exact wording should be pulled from the current AAD guideline directly rather than repeated from memory.

A commentary on spironolactone tolerability in dermatologic practice discussed the general point that spironolactone's potassium-sparing effect means any co-administered agent touching renal or electrolyte physiology deserves attention. The commentary is indexed at PubMed (PMID 34724568). Because this article cannot independently verify the exact wording of a quotation attributed to a specific physician without the original text in hand, the point is paraphrased here rather than presented as a direct quote; an editor with journal access should confirm the original wording before any quotation is restored.

The NIH Office of Dietary Supplements maintains fact sheets covering amino acid supplements and general drug-nutrient interaction principles. ODS fact sheet index. It does not list a specific glycine-spironolactone interaction, consistent with the absence of published data on this pairing.

Frequently Asked Questions