Most drug shortages are an inconvenience: you drive to a different pharmacy, or your doctor swaps you to a similar medication, and life goes on. The Bicillin L-A shortage doesn't work that way for a meaningful share of the people affected by it, because for one specific use, preventing a baby from being born with congenital syphilis, there genuinely isn't a substitute. That's the detail that gets lost in most coverage of this shortage, which tends to either stay at the press-release level ("recovery pushed to 2027") or dive straight into clinician-only dosing tables. This guide sits in between: enough clinical specificity to be actually useful, written for the person standing in a clinic waiting room, not the pharmacist behind the counter.
1. What Bicillin L-A Actually Is (and Why Nothing Else Quite Works)
Bicillin L-A is the brand name for penicillin G benzathine, given as a single deep intramuscular injection. What makes it different from a regular penicillin shot is how slowly it releases into the bloodstream. A standard IV or IM dose of penicillin clears the body within hours. Benzathine penicillin is formulated specifically to release gradually over roughly two to four weeks, maintaining low but steady drug levels the entire time.
That slow release matters because Treponema pallidum, the bacterium that causes syphilis, reproduces very slowly. Killing it requires sustained antibiotic exposure over an extended period, not a quick spike. A fast-clearing penicillin formulation simply doesn't stay in the system long enough to do the job, which is the whole reason this specific, oddly engineered version of an otherwise common antibiotic became the only FDA-approved option for treating syphilis, and the only one recommended during pregnancy.
Why staging matters: How much Bicillin L-A a patient needs depends entirely on how far the infection has progressed. Per CDC guidance, early syphilis, meaning primary, secondary, or early latent, requires a single 2.4 million-unit injection, including during pregnancy. Late latent syphilis or syphilis of unknown duration requires three weekly injections of the same 2.4 million-unit dose. A thorough physical exam and accurate staging aren't just a formality; they determine whether you need one appointment or four.
2. Two Shortages Stacked Into One
It's tempting to describe this as one continuous shortage, but it's really two separate problems that happened to overlap. Understanding both is the difference between assuming "supply will bounce back any month now" and understanding why it hasn't.
Problem one: demand outgrew manufacturing capacity
FDA's original 2023 shortage notice attributed the supply interruption to a combination of rising syphilis diagnoses nationally and manufacturing constraints at Pfizer, at the time the only significant domestic producer. Congenital syphilis cases in the U.S. climbed sharply through the early 2020s, which meant more pregnant patients needing treatment, which meant demand for a slow, specialized manufacturing process outpacing what one company could produce.
Problem two: a 2025 recall over particulate contamination
Just as that first problem showed early signs of easing, a second one hit. On July 10, 2025, Pfizer issued a voluntary recall of specific lots of both the 1.2 and 2.4 million-unit prefilled syringes after particulate matter was identified during visual inspection. Recalls exist for good reason (injecting particulate matter intramuscularly is not something you want to risk), but the timing meant a meaningful chunk of already-scarce inventory came off the market at once, right as CDC was urging jurisdictions to preserve remaining supply for pregnant patients specifically.
Those two problems compounding is the real reason this shortage has outlasted almost every other injectable drug shortage in recent memory, and why the recovery date has kept slipping rather than holding steady.
3. Full Timeline: 2023 to August 2026
| Date | Event |
|---|---|
| 2023 | FDA lists Bicillin L-A as a shortage, citing rising syphilis diagnoses alongside manufacturing constraints at Pfizer, the sole domestic producer |
| Jan 2024 | FDA authorizes temporary import of Extencilline (French benzathine penicillin) to help bridge the gap |
| Jul 10, 2025 | Pfizer issues a voluntary recall of select 1.2 and 2.4 million-unit prefilled syringe lots due to particulate matter found on visual inspection; CDC urges jurisdictions to preserve remaining stock for pregnant patients |
| Jan 5, 2026 | Extencilline is discontinued from U.S. distribution — no longer an available bridge option |
| Jan 21, 2026 | Pfizer extends its estimated shortage recovery to Q4 2026 |
| Mar 6-10, 2026 | FDA authorizes temporary import of Lentocilin (Portuguese benzathine penicillin) as the new bridge alternative |
| Apr 2026 | State and city health departments (New York City, others) issue updated clinician advisories reflecting the Q4 2027 recovery estimate |
| Jun-Jul 2026 | Multiple state health departments (Minnesota, Maine, Nevada) confirm Pfizer has again extended the recovery estimate, this time to Q4 2027, with next delivery of standard-dose syringes pushed to October 2026 |
| Aug 2026 | Shortage remains active; no newer recovery date has been published beyond the Q4 2027 estimate |
4. Current Status: What "Shortage" Looks Like on the Ground
As of this update, the most recent manufacturer guidance, cited by multiple state health departments through July 2026, has King Pharmaceuticals targeting an October 2026 delivery of standard 1.2 and 2.4 million-unit prefilled syringes to wholesalers, a December 2026 delivery of the pediatric 600,000-unit syringes, and a full recovery estimate of the fourth quarter of 2027. None of those are guarantees. This same manufacturer estimate has already moved once in 2026, and injectable drug shortages in general have a track record of recovery dates slipping further once they're set.
The roughly-25% figure comes from outside estimates cited in a July 2026 Minnesota Department of Health clinician bulletin, not an official FDA or CDC statistic, and it isn't verifiable state by state. It's included here because it explains why health departments are rationing rather than distributing on a first-come, first-served basis.
What this means practically: Because national supply is limited and allocated by priority rather than by order date, availability varies significantly by state, by clinic type, and by whether your case is flagged as high-priority (pregnancy, newborn exposure, documented penicillin need). A large hospital system in one city having stock says almost nothing about whether an independent OB practice two states over does.
5. If You're Pregnant: What Actually Happens Now
This is the section that matters most, so it's worth being direct: benzathine penicillin G is the only treatment recommended for syphilis during pregnancy, and the only one proven to prevent congenital syphilis in the baby. Doxycycline, the standard non-pregnancy alternative, crosses into fetal bone and teeth development in ways that make it inappropriate during pregnancy. There is currently no other antibiotic that reliably substitutes for penicillin in this specific situation.
Because of that, CDC has directed health departments and health systems nationally to preserve remaining Bicillin L-A and Lentocilin supply specifically for pregnant patients and infants with confirmed or suspected in-utero syphilis exposure ahead of other uses. In practice, this means:
- Public STI clinics and health department programs generally hold reserved, prioritized allocations, separate from what's available through general hospital or retail-adjacent channels.
- If your OB's office or the hospital pharmacy they use has run out locally, that is not necessarily the end of the road; your local or state health department's STI/STD program is often the next call, and providers can also route through Pfizer's Medical Request Process for individual pregnant patients or neonates when a distributor has no supply. This is typically arranged provider-to-provider rather than patient-to-manufacturer.
- Early syphilis in pregnancy still only requires a single 2.4 million-unit dose, so the actual quantity needed per patient is small; the bottleneck is distribution and allocation, not the total volume any one pregnancy consumes.
Don't wait to bring this up. If you've tested positive for syphilis during pregnancy, tell your prenatal care team immediately and ask directly whether Bicillin L-A or Lentocilin is currently in stock at their site. Treatment timing relative to gestational age affects how well it protects the pregnancy, so delays from supply confusion are worth escalating quickly rather than waiting it out. If your provider's office seems unaware of the shortage or the prioritization pathways, it's reasonable to ask them to check their state health department's most recent Bicillin L-A advisory directly.
6. Penicillin Allergy and Pregnancy: Why the Answer Isn't "Switch Drugs"
This is a genuinely underexplained piece of the puzzle. If you're pregnant, have a documented penicillin allergy, and test positive for syphilis, the standard clinical approach isn't to reach for a different antibiotic class. It's allergy evaluation, and if the allergy is confirmed through testing, penicillin desensitization, a supervised process that temporarily allows the body to tolerate penicillin, followed by treatment with the penicillin itself.
The reasoning is the same as everything else in this section: nothing else reliably prevents congenital syphilis, so the goal is to make penicillin usable rather than to avoid it. This is not something to attempt outside a supervised clinical setting, and it's a conversation worth starting as early as possible with your prenatal care team, ideally the same day a positive syphilis test comes back, rather than after a Bicillin L-A shot has already been scheduled and then delayed by supply issues.
7. If You're Not Pregnant: Doxycycline and Other Options
For non-pregnant adults, CDC guidance does support an oral alternative: doxycycline 100 mg taken twice daily for 14 days for primary, secondary, or early latent syphilis, or for 28 days if the diagnosis is late latent syphilis or of unknown duration. It's worth being honest about the trade-off here, because most articles gloss over it: a single injection with guaranteed adherence is being swapped for a multi-week oral course that only works if you take every dose. Missed doses or an interrupted course are a real risk with any long antibiotic regimen, in a way a one-time shot simply isn't.
Ceftriaxone has limited supporting data as an option for people who can't take or tolerate doxycycline, including for neurosyphilis, but it's considered a second-line choice with less evidence behind it than either penicillin or doxycycline, and it typically requires daily administration for the full course length.
Staying with Bicillin L-A (or Lentocilin)
- Treatment is complete after one visit (early syphilis) or three weekly visits (late latent), with no adherence risk in between
- It's the option with the most extensive track record and the strongest evidence base
- No pregnancy concerns if you become pregnant later, since it's already the recommended option in pregnancy too
Switching to oral doxycycline
- Requires 14 to 28 consecutive days of twice-daily dosing, taken exactly as prescribed
- Not appropriate during pregnancy or if you might become pregnant during the course
- Follow-up testing to confirm the infection has cleared still matters just as much as with the injection
8. The Bicillin C-R Mix-Up: A Different Drug, Not a Workaround
Here's a distinction most shortage coverage skips entirely, and it matters: Bicillin C-R is a different, related product, and it is explicitly not a substitute for Bicillin L-A in syphilis treatment, shortage or no shortage.
Bicillin C-R combines two forms of penicillin in equal parts, half long-acting benzathine penicillin and half short-acting procaine penicillin, in the same total unit dose as Bicillin L-A. That means a full dose of Bicillin C-R only delivers half the long-acting benzathine penicillin that syphilis treatment actually requires. This isn't a theoretical concern. A documented 1998 case in Maryland involved a public STD clinic inadvertently treating syphilis patients with Bicillin C-R instead of Bicillin L-A for months before the error was caught by a provider in a neighboring county, resulting in inadequately treated patients. FDA responded by changing Bicillin C-R's packaging, adding bold red "Not for the Treatment of Syphilis" warnings to the carton and syringe labels.
Where Bicillin C-R is actually appropriate: It's a legitimate, separate treatment for other infections, including strep throat and other upper respiratory infections, skin infections, and scarlet fever, where its combination of a fast initial dose and a longer tail is exactly what's wanted. It just isn't tracked as part of this specific shortage in the same way, and it should never be offered in place of Bicillin L-A when the diagnosis is syphilis. If a clinic suggests it for that purpose, it's worth asking directly whether they mean Bicillin L-A or C-R.
9. Lentocilin and Extencilline: What "Imported Alternative" Really Means
When U.S. supply runs short, FDA has the authority to temporarily allow import of an equivalent product approved in another country, provided it meets safety and effectiveness standards. Two products have played that role during this shortage, though not at the same time.
Extencilline (no longer available)
Extencilline, a French-manufactured benzathine penicillin, was authorized for import in January 2024 and helped bridge earlier phases of the shortage. As of January 5, 2026, it is no longer being distributed in the U.S. If you've seen older articles or state advisories referencing it as a current option, that information is now out of date.
Lentocilin (currently authorized)
Lentocilin, manufactured in Portugal, was authorized for temporary import in March 2026 and is the alternative currently in use. FDA and CDC consider it interchangeable with Bicillin L-A in terms of safety and effectiveness, even though it isn't independently FDA-approved. One detail worth knowing before your appointment rather than during it: reconstituted, a 1.2 million-unit dose of Lentocilin comes out to roughly 4 mL of liquid, compared to about 2 mL for the same dose of Bicillin L-A. In practice, that means some Lentocilin doses are given as two separate intramuscular injections rather than one, simply because of the larger volume, not because the dose itself is different. It's a minor administrative difference, but "why am I getting two shots instead of one" is a reasonable question to have answered ahead of time rather than in the exam room.
10. Strep Throat and Rheumatic Fever Prophylaxis
Syphilis and pregnancy get most of the attention in this shortage, understandably, but Bicillin L-A is also used for a couple of other things worth addressing separately.
Rheumatic fever prophylaxis
Patients recovering from acute rheumatic fever, or living with rheumatic heart disease, are often kept on scheduled Bicillin L-A injections, typically every three to four weeks, for years at a time, to prevent recurrent strep infections that could trigger another rheumatic fever episode. CDC guidance notes that twice-daily oral penicillin V is an accepted alternative prophylactic regimen where injections aren't reliably available, and this is a conversation to have proactively with a cardiologist or infectious disease specialist rather than simply missing a scheduled dose and hoping it doesn't matter.
Strep throat
For a single-dose strep throat treatment, providers have historically used either Bicillin L-A or Bicillin C-R, and C-R in particular remains a reasonable, separately-supplied option for this purpose specifically. If you're being treated for strep throat and told the clinic is out of "Bicillin," it's worth clarifying which formulation they mean, since the shortage pressure on the two products has not been identical.
11. Decision Tree: What Should You Do Right Now?
For strep throat, ask whether Bicillin C-R is available (it's a different, separately-tracked product). For rheumatic fever prophylaxis, ask about oral penicillin V as a bridge if injections are delayed. Don't stop or skip prophylactic treatment without a plan from your specialist.
12. Step-by-Step: If Your Clinic Says They're Out
Say clearly why you need it, and when
Whether it's pregnancy, a newborn's exposure, an active syphilis diagnosis, or ongoing rheumatic fever prophylaxis changes what pathway applies and how urgent the situation is. Make sure the person you're speaking with has that context, not just "I need my Bicillin shot."
Ask specifically about Lentocilin
Some clinics that are out of Bicillin L-A do have Lentocilin, or can access it through their distributor, since it's currently the authorized bridge alternative. It's a reasonable direct question rather than assuming "out of Bicillin" means "no options."
Ask your provider to contact the local or state health department's STI/STD program
These programs frequently hold reserved allocations separate from general hospital or clinic supply, precisely because CDC has directed jurisdictions to prioritize pregnant patients and newborns. This step is usually most effective coming from your provider's office rather than as a direct patient call, though public STI clinics can often see patients directly as well.
For pregnancy or newborn cases, ask about Pfizer's Medical Request Process
When a distributor genuinely has no supply, providers can request product directly from Pfizer for individual pregnant patients or neonates with syphilis. This is a provider-to- manufacturer pathway, so the useful move as a patient is confirming your provider's office knows it exists and is willing to use it.
Don't self-manage a delay
If treatment is genuinely unavailable in your area for more than a few days, that's a situation for your provider to help troubleshoot, not something to wait out quietly, particularly during pregnancy, where timing relative to gestational age matters for how protective treatment ends up being.
13. Cost & Access: Why the Usual Savings Playbook Doesn't Quite Apply
Most of Refill Relay's guides point toward pharmacy discount cards or manufacturer copay programs, and it's worth being upfront that those tools don't map cleanly onto this situation. Bicillin L-A isn't something you typically pick up at a retail pharmacy counter with your own prescription; it's administered in a clinical setting, an OB office, STI clinic, health department, or hospital, and billed as part of that visit rather than as a standalone pharmacy claim. How it's billed, and what it costs out of pocket, depends heavily on where you receive it and how your specific insurance plan handles physician-administered drugs, which is genuinely variable enough that we won't guess at numbers here.
What is worth knowing: many public health department STI and STD clinics provide testing and treatment for syphilis at low or no cost, funded through CDC and state public health grants, regardless of insurance status, specifically because untreated and undertreated syphilis is a public health priority. If cost is a barrier to getting treated promptly, a local health department STI clinic is often a more direct answer than a discount card, and it's also one of the settings most likely to have prioritized Bicillin L-A or Lentocilin access during this shortage. If you're weighing broader prescription cost questions elsewhere in your care, our guide to programs that help pay for prescriptions and our explainer on how patient assistance programs work cover the self-administered side of that picture, and current Medicare Part D changes are worth a look if you're navigating a related prescription on a separate plan.